If a central atom in a molecule has 7 valence electrons and there are two sets of lone pairs, how many valence electrons of the central atom are involved in a bond?

Question

2

7

3

5

Answer 1

To determine how many valence electrons of the central atom are involved in bonding, we can follow these steps:

1. A central atom with 7 valence electrons typically has the following electron configuration with respect to bonding: it can form a maximum of 3 bonds (since each bond typically involves 2 electrons).

2. If there are two sets of lone pairs, this means there are 4 electrons (2 pairs) that are not involved in bonding.

3. Therefore, out of the original 7 valence electrons, if 4 are lone pairs, the number of valence electrons involved in bonding would be:

   \[ 7 \text{ (total valence electrons)} - 4 \text{ (lone pair electrons)} = 3 \text{ electrons} \]

So, the number of valence electrons of the central atom that are involved in a bond is 3.