Question

The number of protons, electrons and neutrons respectively in a molecule of heavy water is:

• A. $10,10,10$
• B. $8,10,11$
• C. $10,11,10$
• D. $11,10,10$

Answer 1

Answer: (A)

The formula for heavy water is $D_{2}O$.

Deuterium contains $1$ proton, $1$ neutron and $1$ electron.

Oxygen contains $8$ protons, $8$ neutrons and $8$ electrons.

Hence, $D_{2}O$ contains $2D$ and $1O$ atoms.

$D_2$ has $2$ protons, $2$ neutrons and $2$ electrons while $O$ has $8$ protons, $8$ neutrons and $8$ electrons.

Hence, $D_{2}O$ contains $10$ protons, $10$ electrons and $10$ neutrons.