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.