how much energy would be needed to remove an electron from an atoms outer energy level forming an ion

Ionization energy, also called ionization potential, in chemistry and physics, the amount of energy required to remove an electron from an isolated atom or molecule. ... first ionization energies of the elementsFirst ionization energies of the elements.

c is the answer to this question. altitude affects the weather because air molecules evaporate.

the answer is 100% density i've answered this question before and done the quiz myself.