Which statement is true according to the quantum model of the atom?
when an electron drops down from a high energy level to a lower one, light energy is emitted.
when an electron jumps up from a low energy level to a higher one, light energy is emitted.
every orbit around the nucleus of an atom is the same energy level.
after they emit light, electrons are sucked into the nucleus of the atom.

Option (a) is the correct answer.

Explanation:

Every orbit has a fixed value of energy which means that energy is quantised. When heat is absorbed by the atom then the electrons go from low energy level to high energy level.

Whereas when heat or energy is released by the atom then electrons move from high energy level to low energy level. As a result, this heat is released in the form of visible light.

Thus, we can conclude that the statement when an electron drops down from a high energy level to a lower one, light energy is emitted, is true according to the quantum model of the atom.

regulation of gene expression. gene expression can be regulated by various cellular processes with the aim to control the amount and nature of the expressed genes. these regulatory proteins bind to dna and send signals that indirectly control the rate of gene expression

explanation:

they deliver oxygen to the blood