The Element Scandium
The element Scandium is the first element in the periodic table to have a more complex electron arrangement than the standard 2, 8, 8, 2 pattern associated with the first 20 elements and with simple Bohr diagrams of electron arrangements. Scandium is a very rare element and as such it is not in major use in any particular industry. The metal is a dark silver colour but is never found as a metal in nature as it is quite reactive. Its most common state is as a positive ion with a 3+ charge. Isotopes of Scandium
There are many possible isotopes of Scandium. All of them have 21 Protons, but the number of neutrons in the nucleus can range from 15 in 36-Scandium to 39 in 60-Scandium. There is however only one stable isotope which is 45-Scandium with 24 neutrons in the nucleus. In any given sample of Scandium this isotope will be the only one present, as the other isotopes all have very short half lives.Electron Arrangement of Scandium To accurately describe the electron structure of this element and all those with atomic numbers of greater than 20, we need to be familiar with the process of obtaining the electron details of the filling of subshells. Using this process we arrive at the electron configuration 1s2 2s2 2p6 3s2 3p6 3d1 4s2. We can see that like the Calcium element Scandium has two electrons in its outer shell. The difference between the two is that Scandium has an extra electron in the 3d subshell. That arrangement can be shown in picture form as follows:
The presence of the electron in the 3d subshell is what makes some compounds of Scandium coloured. The chemistry behind this is complex. In simple terms, there are many energy levels within the 3d subshell which the electron can move between. It gets the energy to move by absorbing and releasing some of the energy from white light, resulting in coloured light. This effect is more pronounced in elements with more d-subshell electrons such as Copper. 
The most common state for Scandium in nature is as the charged ion Sc3+. In this, the atom loses both outer shell electrons and the 3d electron as well, leaving it with the stable electron configuration of 1s2 2s2 2p6 3s2 3p6.
Return from the Element Scandium to Solar Chemistry 1 or return to the Green Planet home page for more Solar Power Facts.
|
