Question

The Sun keeps shining a) mostly by gravitation contraction b) mostly by chemical reactions c) by converting hydrogen to helium. d) by converting hydrogen to carbon. e) by E = mc2. f) by F=G M_1 M_2/R12

Answer 1

The Sun generates energy through nuclear fusion, converting hydrogen into helium, a process that balances gravitational forces and thermal pressure within the Sun's core.

Step-by-step explanation:

How the Sun Produces Energy

The Sun produces energy primarily through the process of nuclear fusion, where protons or hydrogen nuclei (¹H) combine to form helium nuclei (⁴He). This is known as the proton-proton cycle, which is the dominant source of energy production in stars like our Sun. British physicist Lord Kelvin and German scientist Hermann von Helmholtz had proposed gravitational contraction as a source of energy, suggesting that the Sun might be shrinking and thus converting gravitational energy into heat. However, this theory does not account for the vast amounts of energy the Sun has emitted over billions of years. Instead, the Sun's longevity and energy output are sustained by the fusion of hydrogen into helium, with a small amount of mass being converted into energy in accordance with Einstein's equation, E = mc².

Each second, approximately 620 million metric tons of hydrogen undergo fusion in the Sun's core, with about 4 million tons of that mass being turned into energy. This process creates a delicate balance between the outward thermal gas pressure and the inward gravitational forces, maintaining the Sun's stability. The temperature at the Sun's center is maintained at around 15 million K to allow for constant fusion, counteracting any gravitational collapse.

Answer 2

C) by converting hydrogen to helium.

Step-by-step explanation:

The Sun keeps shining because of nuclear fusion processes, which consists in creating helium atoms by combining hydrogen atoms, of an atomic mass less that of helium, in conditions of high core pressure and temperature. In other words, the Sun keeps shining by producing helium at the expense of its hydrogen reserves.

Therefore, the correct answer is C.