Positions of Electrons/energy levels/ atomics structure

Well all atoms have sub levels. Sub level 4,3,2, and 1. They reside in the blocks .

1s

2s, 2p

3s, 3p, 3d

4s, 4p, 4d, 4f

Electrons that can be held:

• s= 2
• p= 6
• d= 10
• f=14

If you look at the periodic table you can see where this all comes in. Period one and period two are all in the s-block and thus if they have a s level for electrons they can all hold only 2.  And it goes on and on to the p block, the d block, and the f block. Energy is more concentrated toward the outer rings of the atom electron shells and as the energy travels inwards , energy is less predominate. 

Here is the periodic table so you can understand the energy levels better.

Now here is an example Mr. Ludwig did with us today.

Say you take helium for example. It has one electron. It only fills up half of a s level. dubbed s exponet 1. Thus is can have more energy. Now take the noble gas Neon. It has ten electrons. SO it fills up the s level on the first shell, the s level on the second shell and fills the p level completely. Noble gases dont react due to all the electrons fitting perfectly into their respective levels/shells.