neutru
gaze rare
II.
stratul M = perioada 3
=> 1s2 2s2 2p6 3s2 3p3
=> Z = 2+2+6+2+3 = 15
III.
₈¹⁶O si ₈¹⁷O
IV.
1s2 2s2 2p6 3s1
=> Z = 11, bloc s,
V.
a) 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p3
b) grupa 15 (V-A), perioada 4
c) 3 straturi, 8 substraturi si 18 orbitali
VI.
a) 1s2 2s2 2p6 3s2 3p6 4s2 3d3 => Z = 23
b) 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p2 => Z = 32
VII.
a) 1s2 2s2 2p6 3s2 3p5 ↑↓ ↑↓ ↑ => 1
b) 1s2 2s2 2p6 3s2 3p6 4s1 ↑ => 1
c) 1s2 2s2 2p3 ↑ ↑ ↑ => 3
d) 1s2 2s2 2p6 ↑↓ ↑↓ ↑↓ => 0
