2.62 Predict the chemical formulas of the compounds formed by the following pairs of ions: (a) Cr3 and Br-, (b) Fe3 and O2-, (c) Hg2 2 and CO3 2-, (d) Ca2 and ClO3 -, (e) NH4 and PO4 3-.

The equation below shows a chemical reaction. a + b + heat —> c + d according to the law of conservation of energy, which statement is true? a. the reactants absorb heat because they have less energy than the products. b. the products release heat because they have more energy than the reactants. c. the reactants generate heat because they have more energy than the products. d. the products require heat to form because they have less energy than the reactants.