At number 21 with 21 electrons and the chemical symbol Sc is Scandium. It is the first in the group known to chemists as Transition Metals. The transition metals are placed in the gap we left in the previous rows between the second and third columns. So why have chemists grouped these elements together and what is different about them. As you know be now, scientists like to group similar things together. It might be objects of the same colour, objects of the same texture, but for chemists it is materials with the same chemical behaviour. The alkali metals from group 1, Lithium, Soduim and Potassium for example, all have one electron in their outer shell and use this electron to bond with other elements. The common trait of the transition metals is that they don't fill all the spaces in the lower energy shells before putting electrons into higher energy shells and this means that they use electrons from more than one shell or energy level to combine with other elements. I suppose you could say that they have rules of their own, maybe they are the teenagers of the periodic table! Because of this transition metal elements give share or bond with different numbers of electrons in different situations.
So what of Scandium? Well it is a metal, present in relatively small amounts in the universe. It doesn't exist in its elemental form in nature so has to be extracted from minerals by scientists. This extraction is difficult and was only done successfully for the first time in 1937. It had been discovered many years before by a Scandinavian chemist, Lars Nilson. Prior to Nilson finding it, this element had been predicted by Mendeleev, the chemist who first put forward the idea that the elements could be organised in a table - the periodic table of elements.
It is light and strong and forms alloys with aluminium that are sometimes used in the planes and bicycles.
Scandium is one of the elements that hasn't been studied a great deal, however researchers continue to explore its characteristics and chemistry so perhaps in the future we will have more interesting uses for it.
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