Which of the following has the greatest mass, in grams? 1) 1 atom of gold (au) 2) 1.0 mol mercury (hg) atoms 3) 2.0 mole of chlorine (cl) atoms 4) 25 atoms of mercury (hg)

Which statement is true about a catalyst? a: a catalyst decreases the rate of the reaction. b. a catalyst is consumed during a chemical reaction. c. a catalyst lowers the activation energy of a reaction. d. a catalyst increases the reactant concentration during a reaction.

In an exothermic reaction at equilibrium, what is the effect of lowering the temperature? a. the reaction makes more products. b. the reaction makes more reactants. c. the reaction is unchanged.

In a covalent bond, two atoms are held together by the attraction between . the number of covalent bonds that an atom can form depends on the number of in the atom.