I don’t understand this at all so i need an explanation and the answer

Explanation:
ok. now as we know that lithium has atomic number 2 so in k shell there are only two electrons. similarly in fluorine atomic number is 9 so in k shell there are 2 electrons in k shell and 7 in l shell . hope u have understood
lithium
protons -- 2
electrons -- 2
neutrons 2