Question

question 5
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which of the following is nonpolar and has a linear molecular geometry?
hcn
no₂⁻
beh₂
nh₃

Explanation:

1. HCN: Has linear geometry, but is polar because C-H and C-N bonds have unequal electronegativity differences, creating a net dipole.
2. NO₂⁻: Has bent (V-shaped) molecular geometry due to a lone pair on N, so it is not linear, and is polar.
3. BeH₂: Has linear geometry (central Be has no lone pairs, bonded to two H atoms). The symmetric linear arrangement cancels out the small bond dipoles, making it nonpolar.
4. NH₃: Has trigonal pyramidal geometry, so it is not linear, and is polar due to the lone pair on N.

Answer:

BeH₂