I need help solving this chemistry question

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.

Describe at least two advantages and two disadvantages of using hydropower as a source of energy.

In one or two grammatically correct sentences, write a definition for the term molecule geometry