Which best describes how an ionic bond forms? a. two molecules share an electron. b. one atom pulls an electron from another atom. c. two atoms share valence electrons. d. two atoms both lose an electron.

Which of the following is most likely true about water in chemical solutions?

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.

Rank the four gases (air, exhaled air, gas produced from from decomposition of h2o2, gas from decomposition of nahco3) in order of increasing concentration of co2