Why is the sunlight written above the arrow in the equation, rather than on either side of it?

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?

According to the tide table below what time of day will the highest tide occur?

Find the mass in grams of 1.37x1020 particles of h3po4