Question

according to the octet rule, most atoms in neutral compounds strive to have how many electrons in their valence shell?
8
10
6
4
which of the following molecules is an exception to the octet rule because the central atom has fewer than eight valence electrons?
co₂
bf₃
nh₃
h₂o

Explanation:

The octet rule states that most atoms in stable compounds strive to have 8 electrons in their valence shell. For the second - part, $BF_3$ is an exception as the boron atom in $BF_3$ has only 6 valence electrons. Hydrogen - containing molecules like $H_2$, $NH_3$, and $H_2O$ follow the octet rule for non - hydrogen atoms and the duet rule for hydrogen.

Answer:

1. A. 8
2. A. $BF_3$