Electrons and Electron Configuration

What is an electron?
An electron (e ) is a subatomic particle with a charge (Q) of 1.6×10-19 coulombs, it is very small and can be found in atoms outside of the nucleus.
Blocks, Periods and Groups
Periods- A period in the periodic table is a row, the rows go from top to bottom starting with one at Hydrogen and Helium.
Groups- In the periodic table this is a column, many elements in the same columns follow trends such as the halogens and alkali metals.
Blocks- There are four blocks in the periodic table:
– Group’s one and two are the s-block (alkali metals) but also include both hydrogen and helium
– Group’s three to twelve are d-block (some transition metals)
– Groups thirteen to eighteen (some transition metals, non-metals and noble gases) are p-block
– The actinides and lanthanides at the bottom of the table are f-block.

Shells and Sub-Shells

Electrons exist in shells of discrete energy levels, each one of these shells can be split up into subshells s,p,d and f just like the blocks. S subshells can hold 2 electrons, p subshells 6, d subshells 10 and f subshells 14 electrons. The shells fill in the same order as the periodic table working from left to right and the top down. The numbers before the
the subshells stand for the shell and the power stands for the number
of electrons in the shell. The numbers of the shells match the period’s
exept in the case of d-block which laggs one behind the rest.