J.R. S. answered 09/30/20
Ph.D. University Professor with 10+ years Tutoring Experience
Mg is in group 2 (2A) and is an s block element. It is in period 3. It has 12 electrons and the orbital diagram would look something like this...
↑↓...↑↓ ... ↑↓ ... ↑↓ ... ↑↓ ...↑↓
1s....2s.....2p......2p......2p.....3s