Question

Light elements with an atomic number less than 20 generally have a neutron to proton ratio equal to
a. 1:1
b. 1.3:1
c. 1.5:1
d. 2:1

Answer 1

The neutron:proton ratio is generally 1:1.

This is because the atomic weight in light elements will be minimum. Also, each light weight element with atomic number less than 20 has a stable isotope. The only exception to this is beryllium.