Question

Why is a $_{2}H{{e}^{4}}$ nucleus more stable than a $_{3}L{{i}^{4}}$ nucleus?
A) The strong nuclear force is larger when the neutron to proton ratio is higher1
B) The laws of nuclear physics forbid a nucleus from containing more protons than neutrons.
C) Force other than the strong nuclear force makes the lithium nucleus less stable.
D) None of the above

Answer 1

The atomic nucleus is a tiny, dense area at the core of an atom made up of protons and neutrons. Nuclear physics is the field of physics concerned with the study and comprehension of the atomic nucleus, including its composition and the forces that tie it together.

Complete answer:
Neutrons and protons make up an atom's nucleus, which are manifestations of more primitive particles known as quarks, which are bound together by the nuclear strong force, in particular stable hadron combinations known as baryons. The nuclear force extends long enough from each baryon to bind neutrons and protons together in the face of the repellent electrical interaction between positively charged protons. The nuclear strong force has a relatively small range, and it effectively vanishes just beyond the nucleus's border.
All neutrons are attracted to one another by the same powerful nuclear force. As a result, the strong nuclear force keeps three protons and one neutron (Li) together just as well as two protons and two neutrons (He). Protons, in particular, repel other protons due to their positive charge. This repulsion seeks to separate a nucleus. Because (He) only has two protons, the protons' repulsion is overcome by the attractive strong nuclear forces. As a result, the nucleus remains intact. However, in (Li), the three protons' mutual repulsion overcomes the strong nuclear forces, and the nucleus disintegrates (or undergoes radioactive decay into a more stable nucleus).
Hence option C is correct.

Note:
The electrically negative charged electrons are held in their orbits around the nucleus by the collective action of the positively charged nucleus. Negatively charged electrons circling the nucleus have a preference for specific configurations and quantities of electrons that keep their orbits stable. Which chemical element an atom represents is determined by the number of protons in the nucleus; the neutral atom will have an equal number of electrons orbiting that nucleus.