Question

The sun is made of plasma (super-heated gas), which is easily compressed by gravitational forces. What process counteracts gravity in the sun?

A) Nuclear radiation pressure
B) Gravity
C) Hydrogen and oxygen bonding to form water
D) Nucleic acid
E) Helium splitting to form Hydrogen

Answer 1

A. Nuclear radiation pressure, caused by nuclear fusion at the sun's core, counteracts the gravitational forces trying to collapse the sun, maintaining a balance that prevents it from contracting.

Step-by-step explanation:

The process that counteracts gravity in the sun is nuclear radiation pressure. This pressure is a result of nuclear fusion, where hydrogen nuclei combine to form helium at extremely high temperatures, releasing tremendous amounts of energy. This energy generates outward thermal gas pressure, which balances the inward gravitational forces attempting to collapse the sun. With temperatures reaching about 15 million K at the sun's core, this balance is sustained, ensuring that the sun does not contract.