A Level Chemistry Energy Level Filling
Electron Energy Level Filling Atoms Remember for atoms fill the 4s before 3d... 1s2s2p3s3p4s3d..(In order of increasing energy) So Calcium (20 electrons)... 1s2 2s2 2p6 3s2 3p6 4s2 And Scandium (21 electrons) 1s2 2s2 2p6 3s2 3p6 4s2 3d1 What about ions? There are two ways of looking at this. Option 1) Although we fill the 4s before the 3d sub level we also empty the 4s sub level before the 3d. So.. Ca atom...
1s2 2s2 2p6 3s2 3p6 4s2 Ca 2+ ion (loses 2 highest energy electron
