Substance a contains 75% carbon and 25% hydrogen. substance b contains 80% carbon and 20% hydrogen. a and b are the same substance. a. true b. false

Which of these best describes an ionic bond?

Light waves can move through , but they travel fastest when they move through a(n) .

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.