In which numbered position would a Period 4 element that is a metal with three valence electrons be located? A) Position 13
B) Position 15
C) Position 20
D) Position 31

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.