Monday, November 14, 2011
From Hydrogen to Tellurium - Palladium
Palladium , Pd is the 46th element. Like the elements I wrote about for the last couple of weeks, palladium is also in the platinum metals group. It's uses are similar to those of rhodium - a catalyst in catalytic converters, electrical connections and jewellery.Palladium has no known biological role and is not present in the human body.
From Hydrogen to Tellurium - Rhodium
Rhodium Rh at number 45 is another slivery white transition metal. It is also in the platinum group.My research tells me that it is used in alloys, jewellery, In electrical applications and as a catalyst. Rhodium is extracted from ore by industry. It is not present in the human body and though the metal itself is not toxic many rhodium compounds are toxic amdalso cause cancer.
Sunday, October 30, 2011
From Hydrogen to Tellurium - RUTHENIUM
Ruthenium
Calendar week 44 in this the International Year of Chemistry means element number 44 and that is Ruthenium with the chemical symbol Ru.. This transition metal has 44 electrons and therefore is in 44th position. This white metal is often grouped with rhodium, palladium, osmium, iridium, and platinum to make up the Platinum group metals.
Ruthenium doesn't react with air at normal temperatures and because of this it doesn't tarnish.
It was first discovered in Russia in the mid 1800s and was named after the latin name for Russia - Ruthenia. Ruthenium is sometimes found as a free metal, often along with other platinum group metals.
Ruthenium is very rare so people are unlikely to come across any ruthenium compounds in normal day to day activities however they these chemicals are considered toxic to humans.
Monday, October 24, 2011
From Hydrogen to Tellurium - TECHNETIUM
Technetium
The 43rd element is Technetium. It has the atomic symbol Tc. My knowledge of this element is very limited. In my research for this blog I discovered it it radioactive - a bye product of the radioactive decay of uranium. It has no biological role and is not found in nature. Apparently it was the first element to be synthesized. It was made by bombarding molybdenum with deuterium.
The 43rd element is Technetium. It has the atomic symbol Tc. My knowledge of this element is very limited. In my research for this blog I discovered it it radioactive - a bye product of the radioactive decay of uranium. It has no biological role and is not found in nature. Apparently it was the first element to be synthesized. It was made by bombarding molybdenum with deuterium.
Sunday, October 16, 2011
From Hydrogen to Tellurium - MOLYBDENUM
Molybdenum
At position 42 is another transition metal - Molybdenum. It sits in the middle of the transition metals with Chromium above it and Tungsten below it. Molybdenum is known by the chemical symbol Mo. It has 4 electrons in its outer orbital and forms compounds with many other elements including hydrogen, fluorine, chlorine, oxygen, nitrogen and sulphur.
Molybdenum doesn't exist as elemental metal in nature but it can be isolated from its oxide. The isolated metal is a silvery white colour.
Small traces of Molybdenum are necessary for life in all species.
Because it doesn't expand or soften when heated to very high temperatures Molybdenum is used in applications that have to withstand very high temperatures. It is added to steel to increase the strength.
Tuesday, October 11, 2011
From Hydrogen to Tellurium - Niobium
Niobium
Next in the series is Niobium - number 41. Scientists use the letters Nb for short. Another metal in the transition metals group, Niobium is a silvery, white, ductile metal with a bluish tinge.. Like many other metals, Niobium does not exist on its own in nature and although scientists found it in the early 1800s it wasn't until it was first extracted from minerals.
Chemically Niobium is very similar to Tantalum, the element that is beneath it in the periodic table. They are so similar that it is difficult to tell them apart.
Most of the Niobium we use today is produced in Brazil.
It is used mixed with other metals, particularly in steel to make it stronger. It is also used with other metals in super conducting magnets. Sometimes it is used in special commemorative coins.
It doesn't have a known biological role in humans, but as it isn't toxic it is sometimes used in jewellery and might be suitable for replacement body parts.
Next in the series is Niobium - number 41. Scientists use the letters Nb for short. Another metal in the transition metals group, Niobium is a silvery, white, ductile metal with a bluish tinge.. Like many other metals, Niobium does not exist on its own in nature and although scientists found it in the early 1800s it wasn't until it was first extracted from minerals.
Chemically Niobium is very similar to Tantalum, the element that is beneath it in the periodic table. They are so similar that it is difficult to tell them apart.
Most of the Niobium we use today is produced in Brazil.
It is used mixed with other metals, particularly in steel to make it stronger. It is also used with other metals in super conducting magnets. Sometimes it is used in special commemorative coins.
It doesn't have a known biological role in humans, but as it isn't toxic it is sometimes used in jewellery and might be suitable for replacement body parts.
Tuesday, October 4, 2011
From Hydrogen to Tellurium - ZIRCONIUM
Zirconium
Using the chemical symbol Zr, Zirconium is the 40th element. It is found in the second position of the second row of transition metals, below Titanium and above Hafnium. The reason scientists are interested in what lies above and below an element is because those elements that are above and below, although they have less or more electron shells, they all have the same number of electrons in their outer shells and it is this electron arrangement that contributes to the chemical behaviour. Hence elements in the same column have similar chemistry.It is not surprising therefore that Zirconium is a gray-white metal that looks like Titanium.
Interesting things about Zirconium are:
It is not found in its elemental state in nature - this means that you don't find lumps of Zirconium metal in the ground.
If you grind it up to make a powder and heat it up, it will burn spontaneously.
Though it has no known biological role, it is not thought to be poison.
It is found in some stars, lunar rock and some terrestrial rocks.
Some Zirconium containing minerals are used in jewellery.
Like titanium, Zirconium is sometimes used by doctors to replace worn out joints.
Monday, September 26, 2011
Yttrium
Yttrium
The 39th element in the series is Yttrium. Yttrium is a transition metal. The transition metals sit in a block in the centre of the table. Yttrium appears in the first position of the second row. This tells us that it has 1 electron in its outer d-orbital.
Although it is never found in nature as a free element, when isolated it is a slivery metal. The surface layer reacts with oxygen giving a passivating layer so Yttrium is stable in air.
It has no role in biology and is thought to cause lung problems in humans.
It was discovered in the late 1700s near Yetterby in Sweeden hence the name -Yttrium.
Yttrium has some interesting uses. As it is very hard, a Yttrium aluminium compound is used to simulate diamond gemstones. Yttrium is also used to start the reaction in which ethene is polymerised to make polythene. When something is used to start a reaction but not used up in the reaction itself scientists call this material a catalyst so we would say that Yttrium catalyses the ethene polymerisation.
Monday, September 19, 2011
From Hydrogen to Tellurium - Strontium
Strontium
Strontium is number 38 and has the chemical symbol Sr. In the same group as Magnesium and Calcium, Strontium is one of the Alkali Earth Metals. Strontium is very reactive with both water and air and therefore doesn't exist naturally in its elemental form. When isolated the metal is a silvery grey colour, however it reacts in air to give a yellowish coloured compound.
It was discovered in Scotland and it is named after the village - Strontian where it was discovered.
Students come across Strontium in their studies because when burned its salts give a characteristic red colour. This characteristic or trait also mean that it is commonly used in fireworks to give a red colour.
Below are links to a couple of video clips showing strontium salts burning with their characteristic red flame.
http://www.youtube.com/watch?v=vltFchuGi0Y
http://www.youtube.com/watch?v=BGd-bCpLDvE&feature=related
Strontium is number 38 and has the chemical symbol Sr. In the same group as Magnesium and Calcium, Strontium is one of the Alkali Earth Metals. Strontium is very reactive with both water and air and therefore doesn't exist naturally in its elemental form. When isolated the metal is a silvery grey colour, however it reacts in air to give a yellowish coloured compound.
It was discovered in Scotland and it is named after the village - Strontian where it was discovered.
Students come across Strontium in their studies because when burned its salts give a characteristic red colour. This characteristic or trait also mean that it is commonly used in fireworks to give a red colour.
Below are links to a couple of video clips showing strontium salts burning with their characteristic red flame.
http://www.youtube.com/watch?v=vltFchuGi0Y
http://www.youtube.com/watch?v=BGd-bCpLDvE&feature=related
Monday, September 12, 2011
From Hydrogen to Tellurium - Rubidium
Rubidium
For the 37th element, we jump back to the left hand side of the periodic table. Rubidium, with the chemical symbol Rb, is an Alkali Metal in the same group as Hydrogen, Lithium, Sodium and Potassium. What you. Should remember about these elements is that each of them have only one electron in their outer shell making them very reactive. In fact, rubidium is the most reactive we have met so far. The increase in reactivity is due to the distance of the outer electrons from the nucleus - the further away the electron is from the nucleus the less tightly the atom can hold onto the electron. Rubidium is very reactive in air and burns spontaneously in water.
Rubidium is a metal, solid at room temperature, but with a melting point of 40 degrees centigrade.
Rubidium is the 23rd most common element in the earth's crust. It is also present dissolved in sea water.
For the 37th element, we jump back to the left hand side of the periodic table. Rubidium, with the chemical symbol Rb, is an Alkali Metal in the same group as Hydrogen, Lithium, Sodium and Potassium. What you. Should remember about these elements is that each of them have only one electron in their outer shell making them very reactive. In fact, rubidium is the most reactive we have met so far. The increase in reactivity is due to the distance of the outer electrons from the nucleus - the further away the electron is from the nucleus the less tightly the atom can hold onto the electron. Rubidium is very reactive in air and burns spontaneously in water.
Rubidium is a metal, solid at room temperature, but with a melting point of 40 degrees centigrade.
Rubidium is the 23rd most common element in the earth's crust. It is also present dissolved in sea water.
Monday, September 5, 2011
From Hydrogen to Tellurium - KRYPTON
Krypton
Krypton is the chemical element with the atomic number 36 and the chemical symbol Kr. In the periodic table it is positioned at the end or right hand side of the fourth row, underneath Helium, Neon and Argon. This tells us that it has the right amount of electrons to fill its outer electron shell. We have already learned that elements with full outer electron shells are not reactive and Krypton is no exception. It is the next member of the inert gas family.
Interestingly, Krypton has been used in defining the length of a meter. According to www.surveyhistory.org The French originated the meter in the 1790s as one/ten-millionth of the distance from the equator to the north pole along a meridian through Paris. It is realistically represented by the distance between two marks on an iron bar kept in Paris. The International Bureau of Weights and Measures, created in 1875, upgraded the bar to one made of 90 percent platinum/10 percent iridium alloy.
In 1960 the meter was redefined as 1,650,763.73 wavelengths of orange-red light, in a vacuum, produced by burning the element krypton (Kr-86). More recently (1984), the Geneva Conference on Weights and Measures has defined the meter as the distance light travels, in a vacuum, in 1/299,792,458 seconds with time measured by a cesium-133 atomic clock which emits pulses of radiation at very rapid, regular intervals.
None of the definitions changed the length of the meter, but merely allowed this length to be duplicated more precisely.
Experiment of the week
Super strong paper
Given that Superman is so strong, it seems fitting to investigate the strength of paper this week.
You will need:
3 A4 sheets of 80g/m2 paper
3 empty spreadable butter containers or similar
a ruler
sand or small weights to load weight onto your bridge
a spoon
adult supervision
What to do
Position 2 of the butter containers 15 cm apart
Use the 3 sheets of paper to bridge the gap
Put the third empty container onto your bridge and slowly fill it with sand.
How much sand can you load onto the bridge before it collapses?
Who can make the strongest bridge?
Post your results and photos below
Tuesday, August 30, 2011
From Hydrogen to Tellurium - BROMINE
Bromine
At number 35 is Bromine with the chemical symbol Br. Another non-metal, Bromine is the first element we have come across that is a liquid at room temperature. It is a red/brown liquid and when heated it boils to produce a red/brown gas at 60°C.
Bromine is in the same group as fluorine and chlorine and is therefore a halogen. Halogens are very reactive, they have space for one more electron in their outer electron shell and are very keen to fill that space by taking an electron from anything that will give them one. In terms of reactivity Bromine is less reactive than fluorine or chlorine but more reactive than iodine which in in the row below it in the table.
Bromine gas has a horrible smell. It is suffocating so not a good idea to have it around. Bromine liquid is corrosive to human tissue. The name Bromine comes from the Greek word Bromos which means stench.
Bromine is extracted from natural brine deposits taken from salt springs.
It is used as a dye, in pesticides and as a flame retardant in plastics.
At number 35 is Bromine with the chemical symbol Br. Another non-metal, Bromine is the first element we have come across that is a liquid at room temperature. It is a red/brown liquid and when heated it boils to produce a red/brown gas at 60°C.
Bromine gas has a horrible smell. It is suffocating so not a good idea to have it around. Bromine liquid is corrosive to human tissue. The name Bromine comes from the Greek word Bromos which means stench.
Bromine is extracted from natural brine deposits taken from salt springs.
It is used as a dye, in pesticides and as a flame retardant in plastics.
From Hydrogen to Tellurium - SELENIUM
Selenium
Selenium is the 34th element, a nonmetal, it has 2 allotropes - a purple/gray one and a red one, the purple/gray one being the most stable. Its chemical symbol is Se.
It is rarely found in nature but occurs as a compound in minerals.
The purple/gray allotrope is a semi conductor and it has an unusual property - it is a better conductor in the light than in the dark.
At number 34, Selenium has 34 electrons. This means that it has 2 spaces in its outer shell - just like oxygen and sulphur. Selenium forms similar compounds to sulphur - SeO2 and H2Se for example
Although it is extremely toxic in large doses, it is present at trace levels in humans and thought to be essential for the correct functioning of the body. We get our Selenium from eating plants and animals that contain Selenium. Brazil nuts have the highest concentration of any food. It is also contained in crab and lobster meat.
Selenium is the 34th element, a nonmetal, it has 2 allotropes - a purple/gray one and a red one, the purple/gray one being the most stable. Its chemical symbol is Se.
It is rarely found in nature but occurs as a compound in minerals.
The purple/gray allotrope is a semi conductor and it has an unusual property - it is a better conductor in the light than in the dark.
At number 34, Selenium has 34 electrons. This means that it has 2 spaces in its outer shell - just like oxygen and sulphur. Selenium forms similar compounds to sulphur - SeO2 and H2Se for example
Although it is extremely toxic in large doses, it is present at trace levels in humans and thought to be essential for the correct functioning of the body. We get our Selenium from eating plants and animals that contain Selenium. Brazil nuts have the highest concentration of any food. It is also contained in crab and lobster meat.
Monday, August 15, 2011
From Hydrogen to Tellurium - ARSENIC
Arsenic
The 33rd element is Arsenic. This element I associate with all sorts of sinister things - murders, poisonings, mystery and intrigue. In Agatha Christie novels it was one of the main causes of death in her victims.
Toxic chemicals are labelled by scientists with the scull and crossbones
to warn users to be especially careful with them, though it is recommended that chemists treat all chemicals as if they might be toxic to prevent any unwelcome surprises.In terms of its properties or traits, Arsenic is a metalloid or semi metal, sitting in the periodic table between the metals and the non-metals. Arsenic occurs in a range of minerals as well as in its elemental form. In its elemental form it is usually a gray crystalline solid but like carbon and phosphorus, it has other allotropes. When heated it goes straight from a solid to a gas - we call this subliming.
Arsenic forms compounds with many other elements - oxygen, sulphur, etc
In the past arsenic compounds have been used as insesticides, weedkillers and wood preservatives. Thanks to the Elements exhibition in the Science Gallery I also learned that Arsenic compounds were also used by interior designers to give a green colour to wall papers.
A modern day use for Arsenic is in the computer industry where it is used for its semiconductor abilities.
Thursday, August 11, 2011
From Hydrogen to Tellurium - GERMANIUM
Germanium
Germanium, with 32 electrons, is the 32nd element in the table. During the week I came across this very colourful periodic table and have included it because it shows the different chemical groups in different colours. As you can see, Germanium is one of the semi metals often called metaloids. It is one that prior to this week I knew very little about.
Its main use is in the computer industry where it is used in semi conductors.
Interestingly, Germanium has a low toxicity in mammals but is highly toxic to some bacteria. Investigations are going on into its use as a means of killing bacteria or treating bacterial infections.
In some factories Germanium dioxide is used to help start the reaction used in the making of PET for drinks bottles.
Saturday, August 6, 2011
From Hydrogen to Tellurium - GALLIUM
Gallium
The 31st element, Gallium is an unusual material. It is not found in nature but can be extracted from minerals.
Gallium, which comes under Aluminium in the periodic table, is a metal. Most metals have high melting points but there are a few exceptions and Gallium is one of those exceptions. You might already know that Mercury, another metal, is liquid at room temperature. Gallium is normally solid at room temperature but it melts at 29 degrees centigrade. This means that its melting point is similar to that of chocolate and any of you who eat chocolate and especially those of you who came to Anyone 4 Science summer camps this year will know that you can melt chocolate in your hand. Well it is exactly the same for Gallium - hold a piece in your hand, which is at 37 degrees centigrade and it will melt! Fairly cool don't you think.
Because aluminium and Gallium look similar a chemistry trick is to make a teaspoon out or gallium instead of aluminium and offer this to your victim to stir their coffee, tea or hot chocolate. Guess what happens to their spoon? - It melts and goes to the bottom of the cup. Check out this disappearing spoon video - http://www.youtube.com/watch?v=QaJ_Yxj9bG8
Gallium also has a big range between its melting and its boiling temperature. This means it is suitable to use in a thermometer.
Another interesting property of Gallium is that is expands as it solidifies. It is unusual for this to happen as most materials contract as they cool. Another exception to this contracting as it cools rule is water. As water freezes it also expands. It is this property that causes pipes to burst when water freezes. If you stored Gallium in a glass container it would crack the container as it cooled.
Check out this cool video made by scientists at Nottingham University showing how to make Gallium beat like a heart. http://www.youtube.com/watch?v=N6ccRvKKwZQ&feature=player_embedded
Experiments of the Week
To show that water expands as it freezes
You will need:
Empty 500 ml PET bottle
water
measuring cylinder
marker
What to do:
Measure 400 mls water into the measuring cylinder and transfer it into the 500ml bottle.
Mark the line showing where the water comes to in the bottle.
Put the bottle of water in the freezer and leave overnight.
Take the bottle our of the freezer and mark the new level of the ice in the bottle.
Allow the liquid to melt.
Fill the bottle to the new mark.
Pour all the water into the measuring cylinder.
Calculate by how much the ice expands.
Experiment 2
Make your own Thermometer
You will need:
Glass bottle.
Water
Food colour
Drinking Straw
modelling clay / blu tack
cold water
basin with hot water
What to do:
Colour some cold water with a few drops of food dye.
Fill the glass bottle with coloured cold water.
Using the modeling clay fix the straw so that it is sealed into but sticking out of the bottle.
Stand the bottle in the basin of hot water
What happens? Leave your comments below.
The 31st element, Gallium is an unusual material. It is not found in nature but can be extracted from minerals.
Gallium, which comes under Aluminium in the periodic table, is a metal. Most metals have high melting points but there are a few exceptions and Gallium is one of those exceptions. You might already know that Mercury, another metal, is liquid at room temperature. Gallium is normally solid at room temperature but it melts at 29 degrees centigrade. This means that its melting point is similar to that of chocolate and any of you who eat chocolate and especially those of you who came to Anyone 4 Science summer camps this year will know that you can melt chocolate in your hand. Well it is exactly the same for Gallium - hold a piece in your hand, which is at 37 degrees centigrade and it will melt! Fairly cool don't you think.
Because aluminium and Gallium look similar a chemistry trick is to make a teaspoon out or gallium instead of aluminium and offer this to your victim to stir their coffee, tea or hot chocolate. Guess what happens to their spoon? - It melts and goes to the bottom of the cup. Check out this disappearing spoon video - http://www.youtube.com/watch?v=QaJ_Yxj9bG8
Gallium also has a big range between its melting and its boiling temperature. This means it is suitable to use in a thermometer.
Another interesting property of Gallium is that is expands as it solidifies. It is unusual for this to happen as most materials contract as they cool. Another exception to this contracting as it cools rule is water. As water freezes it also expands. It is this property that causes pipes to burst when water freezes. If you stored Gallium in a glass container it would crack the container as it cooled.
Check out this cool video made by scientists at Nottingham University showing how to make Gallium beat like a heart. http://www.youtube.com/watch?v=N6ccRvKKwZQ&feature=player_embedded
Experiments of the Week
To show that water expands as it freezes
You will need:
Empty 500 ml PET bottle
water
measuring cylinder
marker
What to do:
Measure 400 mls water into the measuring cylinder and transfer it into the 500ml bottle.
Mark the line showing where the water comes to in the bottle.
Put the bottle of water in the freezer and leave overnight.
Take the bottle our of the freezer and mark the new level of the ice in the bottle.
Allow the liquid to melt.
Fill the bottle to the new mark.
Pour all the water into the measuring cylinder.
Calculate by how much the ice expands.
Experiment 2
Make your own Thermometer
You will need:
Glass bottle.
Water
Food colour
Drinking Straw
modelling clay / blu tack
cold water
basin with hot water
What to do:
Colour some cold water with a few drops of food dye.
Fill the glass bottle with coloured cold water.
Using the modeling clay fix the straw so that it is sealed into but sticking out of the bottle.
Stand the bottle in the basin of hot water
What happens? Leave your comments below.
Friday, August 5, 2011
From Hydrogen to Tellurium - Zinc
Zinc
The last element in the first row of transition metals is Zinc. With an atomic number of 30, Zinc has 30 electrons. This means that Zinc has a full 4S orbital and also a full 3D orbital, but empty 4P orbitals and as a result of this Zinc is quite reactive and has lots of chemical similarities to Magnesium.
Zinc is a metal, not found in the elemental state but normally found in nature as Zinc Sulphide. Zinc metal is extracted from this mineral. We know that humans have known about Zinc for a long time because Zinc is combined with copper to give bronze which was used extensively in the bronze age. The Bronze age started about 3300BC and continued until 1200BC.
Zinc is a bluish white metal with a melting point of 419 degrees centigrade. Although this is very hot, it is much lower than the metals we have been considering over the last few weeks. The surface of the metal reacts quickly with air but the layer of oxide that is formed is unreactive and makes a layer which is difficult to penetrate.
This unreactive surface layer is widely used to help prevent oxidation of other metals. To prevent steel oxidising it is covered with a thin layer of Zinc. Zinc forms a tough exterior layer and prevents the steel from rusting.
Zinc is also used in batteries.
Zinc is an essential trace element for humans, plants and animals. We get zinc in our diets from red meats, beans, some nuts and seeds.
Other interesting facts about Zinc compounds include the following
It is used in sunscreens to prevent sun burn
It helps to prevent nappy rash in babies
It is used in toothpaste to prevent bad breath
It is used to kill germs - particularly bacteria and fungi
Experiment of the Week
Make your own battery
You will need:
a copper coin
a zinc nail
tissue paper
salt water
a volt meter or a 3V buzzer
What to do:
dip the tissue paper into the salt water
Make a sandwich - copper, soaked tissue, zinc
either connect the voltmeter to the 2 metals and record the voltage or complete the circuit using the buzzer with the red wire attached to the copper and the black wire attached to the zinc.
Post your results in the comments section below.
The last element in the first row of transition metals is Zinc. With an atomic number of 30, Zinc has 30 electrons. This means that Zinc has a full 4S orbital and also a full 3D orbital, but empty 4P orbitals and as a result of this Zinc is quite reactive and has lots of chemical similarities to Magnesium.
Zinc is a metal, not found in the elemental state but normally found in nature as Zinc Sulphide. Zinc metal is extracted from this mineral. We know that humans have known about Zinc for a long time because Zinc is combined with copper to give bronze which was used extensively in the bronze age. The Bronze age started about 3300BC and continued until 1200BC.
Zinc is a bluish white metal with a melting point of 419 degrees centigrade. Although this is very hot, it is much lower than the metals we have been considering over the last few weeks. The surface of the metal reacts quickly with air but the layer of oxide that is formed is unreactive and makes a layer which is difficult to penetrate.
This unreactive surface layer is widely used to help prevent oxidation of other metals. To prevent steel oxidising it is covered with a thin layer of Zinc. Zinc forms a tough exterior layer and prevents the steel from rusting.
Zinc is also used in batteries.
Zinc is an essential trace element for humans, plants and animals. We get zinc in our diets from red meats, beans, some nuts and seeds.
Other interesting facts about Zinc compounds include the following
It is used in sunscreens to prevent sun burn
It helps to prevent nappy rash in babies
It is used in toothpaste to prevent bad breath
It is used to kill germs - particularly bacteria and fungi
Experiment of the Week
Make your own battery
You will need:
a copper coin
a zinc nail
tissue paper
salt water
a volt meter or a 3V buzzer
What to do:
dip the tissue paper into the salt water
Make a sandwich - copper, soaked tissue, zinc
either connect the voltmeter to the 2 metals and record the voltage or complete the circuit using the buzzer with the red wire attached to the copper and the black wire attached to the zinc.
Post your results in the comments section below.
Tuesday, August 2, 2011
From Hydrogen to Tellurium - COPPER
Copper
The 29th element is a well known element - Copper. Another metal, most children will be able to tell you that 1, 2 and 5 cent Euro coins are Copper.
This metal is a pinkish brown colour. When polished it is shiny but it reacts with air to give a dull oxide. We also associate a green colour with Copper. If you wear a Copper bracelet your will get a green deposit on it. Some churches have copper decorating their roofs. This Copper started out life as a shiny metal but over time, reacting with the air and pollutants in the air it has become green.
This is a photo of the church in Rathmines on the south side of Dublin. The green roof is made from Copper.
Copper has 29 electrons. They fill up the orbitals as follows: 1S 2, 2S 2, 2P 6, 3S 2, 3P 6, 4S 1, 3D 10. This means that the 3D orbital is full as a D orbital can fit 10 electrons. This is the first element we come across to have a full D orbital.
Copper is a good conductor of heat and of electricity. It is used in wires for carrying electricity.
Copper is also used in many of our homes for the plumbing. The copper pipes carry the water around the house. Where we live the water is slightly acidic as it comes through granite to get to our well. I can see the effects of this in our bathroom and in our hair. THe slightly acidic water travelling through the Copper pipes reacts with and dissolves some of the Copper. I see this as a green deposit in our shower tray and basins. It also shows up in the hair of blond family members - wash your blond hair in this Copper containing water and after a while your hair will have a green hue. This is especially visible on sunny days when the sun shines on the hair. What is causing the hair to appear green? The Copper from the pipes chelates or bonds to the hair.
Can you melt Copper? The answer is yes, but not in the flame of a candle which just doesn't get hot enough. Copper melts at 1084 degrees centigrade.
Copper isn't magnetic but an interesting experiment to do is to test the 1, 2 and 5 cent Euro coins to see if they are magnetic. What did you find? Can you explain this?
Experiment of the Week
Take Copper from a coin and deposit it on a nail.
You will need:
small cup or beaker
salt
vinegar
about 10 copper coins - dirty ones are fine
kitchen roll
nail
What to do:
Half fill a small beaker with vinegar (use approx 20 - 30 mls)
Add a teaspoon of salt.
Put your coins into the salt vinegar mix and leave for about 30 minutes.
Remove the coins and leave to dry on a piece of kitchen roll. Do not discard the liquid as you will need it for the next part of the experiment.
Dip a nail into the salt vinegar mixture and leave for about 10 minutes.
Remove the nail and examine it carefully.
What has happened?
Return to the coins. What has happened to them?
Explain your observations.
Leave your comments below.
Monday, August 1, 2011
From Hydrogen to Tellurium - NICKEL
Nickel
Element 28 is Nickel which is another metal from the transition metal series. The name Nickel is familiar to many people, not because they know it as another element but because of the slang name given to the US 5 cent coin.
Although known as a Nickel, the 5 cent in fact is made of a mixture of 75% copper and 25% nickel. In spite of this it has the silvery colour of Nickel.
Like Iron and Cobalt, Nickel is magnetic, however the US Nickel is not magnetic as it doesn't contain enough Nickel to make it magnetic.
Nickel is used in stainless steel iron with 18% chromium and 8% Nickel.
Much "good" cutlery though referred to as silver isn't actually silver but nickel silver. Nickel silver is an alloy of copper, nickel and zinc. This same alloy is also used for making musical instruments and costume jewellery.
At the summer camps this year we have been looking at melting points. We found that sugar would melt at 186 degrees centigrade. Nickel also melts but at the much hotter temperature of 1455 degrees centigrade.
Element 28 is Nickel which is another metal from the transition metal series. The name Nickel is familiar to many people, not because they know it as another element but because of the slang name given to the US 5 cent coin.
Although known as a Nickel, the 5 cent in fact is made of a mixture of 75% copper and 25% nickel. In spite of this it has the silvery colour of Nickel.
Like Iron and Cobalt, Nickel is magnetic, however the US Nickel is not magnetic as it doesn't contain enough Nickel to make it magnetic.
Nickel is used in stainless steel iron with 18% chromium and 8% Nickel.
Much "good" cutlery though referred to as silver isn't actually silver but nickel silver. Nickel silver is an alloy of copper, nickel and zinc. This same alloy is also used for making musical instruments and costume jewellery.
At the summer camps this year we have been looking at melting points. We found that sugar would melt at 186 degrees centigrade. Nickel also melts but at the much hotter temperature of 1455 degrees centigrade.
Friday, July 29, 2011
From Hydrogen to Tellurium - COBALT
Cobalt
Though I got off to a good start, writing the blog each week , particularly during the busy weeks of the summer camps has proved more difficult that I thought. Now that there is a break in the camps for a few weeks hopefully I will get a chance to catch up.
Element number 27 is Cobalt. This element has 27 electrons and is another transition metal. Like many other elements Cobalt doesn't exist in nature in its elemental state but can be produced by smelting. Elemental Cobalt is a sliver, grey metal.
Again like the other transition metals, Cobalt forms compounds with many different elements and these compounds are varied in colour. One of the best known uses of a Cobalt compound is in cobalt blue, the dye that is used in pottery and glass to give a deep blue colour. There are many examples of this blue glass at the Elements Exhibition in the Science Gallery in Trinity. The exhibition opened 2 weeks ago and runs until mid September and is certainly worth a visit.
Cobalt is essential to all animals, including humans. It is found in vitamin B12. We need vitamin B12 to keep our brain and nervous system functioning properly and also for the production of blood. Vitamin B12 is found in fish, shellfish, meat - especially liver, poultry, eggs, dairy products and milk.
Cobalt chloride is known by leaving certificate students as a chemical used to test for the presence of water in desiccants. The anhydrous or dry version is blue and the hydrated version is pink. This colour change is reversible so if you dry pink cobalt chloride it reverts to its blue colour.
Another interesting fact about Cobalt is that it is magnetic.
Though I got off to a good start, writing the blog each week , particularly during the busy weeks of the summer camps has proved more difficult that I thought. Now that there is a break in the camps for a few weeks hopefully I will get a chance to catch up.
Element number 27 is Cobalt. This element has 27 electrons and is another transition metal. Like many other elements Cobalt doesn't exist in nature in its elemental state but can be produced by smelting. Elemental Cobalt is a sliver, grey metal.
Again like the other transition metals, Cobalt forms compounds with many different elements and these compounds are varied in colour. One of the best known uses of a Cobalt compound is in cobalt blue, the dye that is used in pottery and glass to give a deep blue colour. There are many examples of this blue glass at the Elements Exhibition in the Science Gallery in Trinity. The exhibition opened 2 weeks ago and runs until mid September and is certainly worth a visit.
Cobalt is essential to all animals, including humans. It is found in vitamin B12. We need vitamin B12 to keep our brain and nervous system functioning properly and also for the production of blood. Vitamin B12 is found in fish, shellfish, meat - especially liver, poultry, eggs, dairy products and milk.
Cobalt chloride is known by leaving certificate students as a chemical used to test for the presence of water in desiccants. The anhydrous or dry version is blue and the hydrated version is pink. This colour change is reversible so if you dry pink cobalt chloride it reverts to its blue colour.
Another interesting fact about Cobalt is that it is magnetic.
Monday, June 27, 2011
From Hydrogen to Tellurium - IRON
IRON
Most people are familiar with the 26th element - Iron. Its first claim to fame is from the Iron Age. This period of history extended from about 800BC to about 100BC. Prior to this we had had the Stone and then the Bronze age. The discovery of Iron led to great advances in civilization. Instead of having to mould tools, smiths were able to heat the iron and beat it into shape.
Though the 6th most common element in the universe, Iron is the most common element in the planet - most of the outer and inner core of the earth are made up of Iron. It is also essential for life. Haemoglobin in our blood is an iron containing molecule. A shortage of Iron in the human body leads to anemia. To prevent this Iron is added to some staple foodstuffs such as breakfast cereals.
So Iron has the chemical symbol Fe. Like manganese its symbol is made up of 2 sequential alphabetic letters, however Fe are sequential when you are saying the alphabet backwards.
Iron is very reactive - it reacts with oxygen to form rust. This rust then flakes off leaving the metal surface exposed so more rust formation occurs. Because Iron rusts so readily there are not many ancient pieces of iron from the Iron age still in existence.
Iron is mixed with Carbon to form steel. Steel is stronger than Iron.
Experiment of the Week
Extract Iron from Breakfast cereal.
You will need:
100g Cereal fortified with iron
A large ziploc bag
A magnet - it is a good idea to cover the magnet with sticky tape before doing this experiment as it is very difficult to remove the iron filings from the magnet when you have finished.
Magnifying glass
What to do:
Pour the cereal into the ziploc bag.
Put the magnet into the bag
Seal the bag
Shake the bag making sure the magnet moves around all the cereal.
Remove the magnet and examine it using a magnifying glass.
You should see little iron filings on the magnet.
Most people are familiar with the 26th element - Iron. Its first claim to fame is from the Iron Age. This period of history extended from about 800BC to about 100BC. Prior to this we had had the Stone and then the Bronze age. The discovery of Iron led to great advances in civilization. Instead of having to mould tools, smiths were able to heat the iron and beat it into shape.
Though the 6th most common element in the universe, Iron is the most common element in the planet - most of the outer and inner core of the earth are made up of Iron. It is also essential for life. Haemoglobin in our blood is an iron containing molecule. A shortage of Iron in the human body leads to anemia. To prevent this Iron is added to some staple foodstuffs such as breakfast cereals.
So Iron has the chemical symbol Fe. Like manganese its symbol is made up of 2 sequential alphabetic letters, however Fe are sequential when you are saying the alphabet backwards.
Iron is very reactive - it reacts with oxygen to form rust. This rust then flakes off leaving the metal surface exposed so more rust formation occurs. Because Iron rusts so readily there are not many ancient pieces of iron from the Iron age still in existence.
Iron is mixed with Carbon to form steel. Steel is stronger than Iron.
Experiment of the Week
Extract Iron from Breakfast cereal.
You will need:
100g Cereal fortified with iron
A large ziploc bag
A magnet - it is a good idea to cover the magnet with sticky tape before doing this experiment as it is very difficult to remove the iron filings from the magnet when you have finished.
Magnifying glass
What to do:
Pour the cereal into the ziploc bag.
Put the magnet into the bag
Seal the bag
Shake the bag making sure the magnet moves around all the cereal.
Remove the magnet and examine it using a magnifying glass.
You should see little iron filings on the magnet.
Friday, June 24, 2011
From Hydrogen to Tellurium - Manganese
Manganese
The first interesting thing I notice about this, the 25th element in the periodic table is that it is the only element in the periodic table whose chemical symbol consists of two sequential letters in the alphabet - Mn. Although Manganese, which is a metal does exist in nature it is not something I have ever knowingly come across. Most of my experience with Manganese is in the Manganese containing compound - Potassium Permanganate KMnO4
Potassium permanganate, which will cause purple stains if it comes in contact with your skin is often used in school and college chemistry experiments. I have only learned recently that it is also used to sterilise water and wounds and because of these properties and the fact that when mixed with ground up glucose tablets the friction causes it to ignite it is often included in survival kits.
Anyway to get back to the element itself........It is often used to prevent steel rusting.
Because Manganese compounds are often coloured they are used as pigments
The first interesting thing I notice about this, the 25th element in the periodic table is that it is the only element in the periodic table whose chemical symbol consists of two sequential letters in the alphabet - Mn. Although Manganese, which is a metal does exist in nature it is not something I have ever knowingly come across. Most of my experience with Manganese is in the Manganese containing compound - Potassium Permanganate KMnO4
Potassium permanganate, which will cause purple stains if it comes in contact with your skin is often used in school and college chemistry experiments. I have only learned recently that it is also used to sterilise water and wounds and because of these properties and the fact that when mixed with ground up glucose tablets the friction causes it to ignite it is often included in survival kits.
Anyway to get back to the element itself........It is often used to prevent steel rusting.
Because Manganese compounds are often coloured they are used as pigments
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