Answer:
a. 0, 4, 0
b. 1, 3, 0
Explanation:
a.
In the picture we can see a Lewis structure for ClO₄⁻ in which all the atoms obey the octet rule, that is, they have 8 electrons in the valence shell.
The number of unshared pairs (lone pairs) on the central Cl atom is: 0
The central Cl atom forms 4 single bonds.
The central Cl atom forms 0 double bonds.
For other resonance structures these numbers can change.
b.
In the picture we can see a Lewis structure for NH₃ in which N obeys the octet rule and H atoms complete the valence shell with 2 electrons (duet).
The number of unshared pairs (lone pairs) on the central N atom is: 1
The central N atom forms 3 single bonds.
The central N atom forms 0 double bonds.
