Question

In which isotope is the strong nuclear force not strong enough to balance electrostatic forces between protons?

Answer 1

In all nuclei above atomic number 83, the strong nuclear force is not strong enough to balance the electrostatic repulsion between protons. Nuclei like deuterium, carbon-13, and neon-21 are all stable. But elements like uranium-238 are radioactive. U-238 (Z = 92) has a half-life of about 4.5 billion years.

Answer 2

Explanation:

It is known that protons are positively charged and an they reside inside the nucleus of an atom. So, due to like charges protons repel each other and this force is known as electrostatic force of repulsion.

But a strong force that binds the protons and neutrons together is called nuclear binding energy.

Therefore, when there is large difference in the number of protons and neutrons then electrostatic force of repulsion overcomes the nuclear binding energy causing the atom to become unstable.

For example, $^{226}_{88}Ra$ is an unstable atom as it has 88 protons and 138 neutrons. Hence, this atom will decay.