15. Evaporation is A. the conversion of a liquid into a B. the conversion of a solid into a vapor. C. the conversion of a vapor into a liquid. D. the conversion of a vapor into a solid. E. All answers are correct. 16. Ice floats on liquid water because A. the molecules are closer together in ice than in liquid water. B. the molecules are farther apart in ice than in liquid water. C. ice is denser than liquid water. D. convection currents caused by temperature differences push upwards on the ice. E. water vapor is less dense than liquid water. 17. In a chemical equation A. the reactants are on the right of the yields arrow. B. reactants and products are on both sides of the yields arrow. C. the products are on the left of the yields arrow. D. the reactants are on the left of the yields arrow. E. the number of atoms of each element may differ on the two sides of the yields arrow. 18. An acid A. has a value above seven on the pH scale. B. is a chemical that takes hydrogen ions from a solution. C. has a value of seven on the pH scale. D. is a chemical that adds hydrogen ions to a solution. E. All answers are correct. 19. A base A. has a of 7 on the pH scale. B. is a chemical that adds hydrogen ions to a solution. C. is a chemical that absorbs hydrogen ions from a solution. D. has a value below 7 on the pH scale.
15. Evaporation is A. the conversion of a liquid into a B. the conversion of a solid into a vapor. C. the conversion of a vapor into a liquid. D. the conversion of a vapor into a solid. E. All answers are correct. 16. Ice floats on liquid water because A. the molecules are closer together in ice than in liquid water. B. the molecules are farther apart in ice than in liquid water. C. ice is denser than liquid water. D. convection currents caused by temperature differences push upwards on the ice. E. water vapor is less dense than liquid water. 17. In a chemical equation A. the reactants are on the right of the yields arrow. B. reactants and products are on both sides of the yields arrow. C. the products are on the left of the yields arrow. D. the reactants are on the left of the yields arrow. E. the number of atoms of each element may differ on the two sides of the yields arrow. 18. An acid A. has a value above seven on the pH scale. B. is a chemical that takes hydrogen ions from a solution. C. has a value of seven on the pH scale. D. is a chemical that adds hydrogen ions to a solution. E. All answers are correct. 19. A base A. has a of 7 on the pH scale. B. is a chemical that adds hydrogen ions to a solution. C. is a chemical that absorbs hydrogen ions from a solution. D. has a value below 7 on the pH scale.
Chemistry%20of%20Life.docx