Methane, or ch4, is an example of a molecule whose atoms are held together by which of the following?
a. hydrogen bonds
b. covalent bonds
c. metallic bonds
d. ionic bonds

If a solution is considered basic, then a) the hydroxide ion and hydronium ion concentrations are equal. b) the hydroxide ion concentration is less than the hydronium ion concentration. c) the hydronium ion concentration is greater than the hydroxide ion concentration. d) the hydroxide ion concentration is greater than the hydronium ion concentration.

When the mercury level in a barometer decreases that atmospheric pressure has

Which of the following is a physical property flammability heat of combustion solubility and toxicity