Which of the following statements correctly describes energy levels?

A. Electrons can never move to a higher or lower energy level.
B. In its outermost energy level, oxygen has 4 valence electrons
C. The second energy level holds a maximum of eight electrons.
D. The greater the energy of the level, the father away it is from the nucleus.

What do think the answer is and why?

Oxygen is 1s2 2s2 2p4

The correct statement that describes energy levels is C. The second energy level holds a maximum of eight electrons.

To understand this concept, we need to know a bit about the structure of an atom. Atoms consist of a positively charged nucleus, containing protons and neutrons, surrounded by negatively charged electrons. Electrons are arranged in energy levels or shells, which are located at increasing distances from the nucleus.

The first energy level, also known as the K shell, is closest to the nucleus and can hold a maximum of two electrons. The second energy level, called the L shell, is located further away from the nucleus and can hold a maximum of eight electrons. The third energy level, which is the M shell, can hold up to 18 electrons. This pattern continues as we move to higher energy levels.

Let's take a look at the other statements mentioned:

A. Electrons can never move to a higher or lower energy level: This statement is incorrect. Electrons can indeed move to higher or lower energy levels through the absorption or emission of energy by the atom.

B. In its outermost energy level, oxygen has 4 valence electrons: This statement is incorrect. Oxygen, with atomic number 8, has a configuration of 2-6. Therefore, it has six valence electrons in its outermost energy level.

D. The greater the energy of the level, the farther away it is from the nucleus: This statement is incorrect. While it is true that higher energy levels are further from the nucleus, the increase in energy is not solely determined by the distance. It is also influenced by factors such as the number of protons, atomic radius, and shielding effect.

Therefore, the correct option is C, which states that the second energy level holds a maximum of eight electrons.