Why does a fluorine ion have a charge of -1

How to solve 4 nh3(g) + 5 o2(g) > 4 no(g) + 6 h2o(g) in chemistry

Calcium hydride (cah2) reacts with water to form hydrogen gas: cah2(s) + 2h2o(l) → ca(oh)2(aq) + 2h2(g) how many grams of cah2 are needed to generate 45.0 l of h2 gas at a pressure of 0.995 atm and a temperature of 32 °c?

C3h8o3 - glycerol major species present when dissolved in water