Question

Consider the following molecules/ions: I. BF3 II. CH4 III. BeCl2 IV. CO2 V. OF2. The central atom cannot complete an octet in which compound(s)?

Option 1: Both I and III
Option 2: Both II and III
Option 3: Only III
Option 4: Only II

Answer 1

The central atom in BF3 and BeCl2 cannot complete an octet.

Step-by-step explanation:

The central atom in BF3, BeF2, and OF2 cannot complete an octet. In BF3, the boron atom only has six electrons surrounding it, while the fluorine atoms each have a full octet.

This makes the boron atom electron deficient and reactive. Similarly, in BeCl2, the beryllium atom only has four electrons surrounding it, while the chlorine atoms each have a full octet. Finally, in OF2, the oxygen atom only has six electrons surrounding it, while the fluorine atoms each have a full octet. Therefore, the correct answer is Option 1: Both I and III.