Elements with three p-electrons....
That would be N, P, As, Sb, and Bi -- elements in group 15
For example, energy diagram showing "empty" orbitals up through the 3p.
.....3p __ __ __
3s __
.....2p __ __ __
2s __
1s __
Energy diagram of phosphorous showing three unpaired electrons in 3p-sublevel
.....3p ↑_ ↑_ ↑_
3s ↑↓
.....2p ↑↓ ↑↓ ↑↓
2s ↑↓
1s ↑↓
According to Hund's rule, the electrons singly occupy the p-orbitals, and all have the same spin.
Answer:
Transition metals, alkali metals, alkaline earth metals Transition metals - Middle of the periodic chart, only average reactivity. alkali metals - As mentioned above, very reactive. Bad choice, going from lower reactivity to higher reactivity.
Hope this answer is right!
The percent of O in Cr₂O₃ : 31.58%
<h3>Further explanation</h3>
Given
Cr = 52.00 amu, O = 16.00 amu
Required
The percent of O
Solution
MW Cr₂O₃ = 2 x Ar Cr + 3 x Ar O
MW Cr₂O₃ = 2.52+3.16
MW Cr₂O₃ =152 amu
