A. ns²np³ — half-filled p-subshell giving extra stability
2.
Why does nitrogen NOT form NX₅ (pentahalides) while phosphorus forms PCl₅?
A.
Nitrogen has a smaller atomic radius than phosphorus so it repels halogen atoms
B.
NX₅ compounds are thermodynamically unstable for all Group 15 elements
C.
Nitrogen lacks d-orbitals in its valence shell (n=2 has only s and p orbitals), so it cannot expand its octet beyond 4 bonds; phosphorus (n=3) has available 3d orbitals to accommodate 5 bonds
D.
Nitrogen is too electronegative to form bonds with halogens
C. Nitrogen lacks d-orbitals in its valence shell (n=2 has only s and p orbitals), so it cannot expand its octet beyond 4 bonds; phosphorus (n=3) has available 3d orbitals to accommodate 5 bonds
3.
The INERT PAIR EFFECT in Group 15 elements explains why:
A.
Electronegativity increases from N to Bi
B.
The metallic character decreases down the group
C.
All Group 15 elements prefer -3 oxidation state exclusively
D.
The stability of +5 oxidation state decreases and +3 oxidation state increases down the group — the ns² electrons become increasingly reluctant to participate in bonding
D. The stability of +5 oxidation state decreases and +3 oxidation state increases down the group — the ns² electrons become increasingly reluctant to participate in bonding
4.
The stability of +5 oxidation state in Group 15 decreases down the group. The ONLY well-characterised Bi(V) compound is:
