Answer:
D. a cation that has a smaller radius than the atom.
Explanation:
When electrons are removed from the outermost shell of a calcium atom, the atom becomes a cation that has a smaller radius than the atom.
There are supposed to be numbers in these places:
" _____ of methane"
" ... pressure of exactly _____ "
" ... temperature of _____ "
I've seen a lot of questions with missing numbers before, but I think this is the first time I ever saw a question where even the number of significant digits to round the answer to is missing.
"Round your answer to _____ significant digits."
So E = 2x10^-3W/m^2*(π*(3.0x10^-3m)^2)*1min*60s... = 3.4x10^-6J
Frequency refers to how often something happens. Period refers to the time it takes something to happen. Frequency is a rate quantity. Period is a time quantity. Frequency is the cycles/second