Lithium has an atomic number of 3. how many electrons are there in the outermost (valence) shell?

The answer should be 1.

Atmoic number means the number of protons in an atom, (an atom contains protons, neutrons, and electrons) and the number of protons also equals to the number of electrons in an atom.

From that, we can know that Lithium has 3 electrons in total.

Since the 1st electron shell only allows 2 electrons, so the remaining 1 must be in the 2nd shell, which is also the out most shell since there's no more electrons.

Therefore, the answer is 1.

Okay well gravitational energy is matter forced by gravity making energy though the kinetic energy then the electric energy produces electricity from the kinetic energy and the kinetic energy gets its energy from the gravitational energy. was that the answer you wanted or something else?  

Answerhund's rule;