the formula of the compound that is formed between chlorine and calcium is CaCl2
explanation
chlorine (non metal) react with Calcium ( a metal) to form an ionic compound CaCl2
Ionic compound is formed when metal loses electrons to form cation ( a positively charged ion) while non metal gains electrons to form anion ( a negatively charged ion)
An ionic compound is formed when calcium metal(Ca) loses two electron to form Ca2+ cation , while 2 chlorine atom gain one electron each to form cl- anions.
when writing down the formula of ionic compound cation symbol is written first followed by anion symbol.
Therefore the formula of ionic compound formed between chlorine and calcium is CaCl2
I'm guessing the photo means photosynthesis. In that case, it is solar energy to chemical energy. Radiant energy and solar energy is kind of the same thing, so 4th answer.