"On some parts of Mars, it gets cold enough for a gas to freeze out of the atmosphere that does not freeze out by itself at the temperatures and pressures on Earth. This gas makes up some of the polar caps on Mars and is:"

Carbon dioxide

Explanation:

In general, carbon dioxide is a odorless, colorless gas formed by burning and respirating carbon and organic compounds. It is naturally present in air (approximately 0.03 per cent) and is absorbed in photosynthesis by plants.

Mars is the fourth planet from the Sun and the second smallest after Mercury in the Solar System. Mars has polar caps , but unlike Earth, these caps are made of carbon dioxide ice and water ice.

Carbon dioxide has makes up the some of the polar caps of the max planet.

because the two particles have an equal charge, the charges will cancel out and give the atom an overall charge of 0. so, if at atom has 35 protons in the nucleus, we could expect it to have 35 electrons orbiting that nucleus.