The reaction CFCl3 + UV Light -> CFCl2 + Cl does not need another reactant as with CFCl3 because the reaction itself is reactive to light. Note that there are reactions that are sensitive to light to form products and when this type of reaction are not exposed to light, no reaction occurs.
Electrons are orbiting the nucleus in the fxed way paths located in solid sphere
i think it's I
I was confused by IV then search on gg and it said ZnSO4 should be Zn2SO4 instead but still im not sure Zn2SO4 is real