What would be an evidence of release in energy?

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?

How many neutrons does a atom of cobalt have?

At stp, which substance is the best conductor of electricity? a. nitrogen b. neon c. sulfur d. silver