How many grams of ^16N will be left from a 16.0 g sample after 21.6 s

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.

Why are people not able to scuba dive in the deep part of the ocean

Can someone me with 1 to 4 plz. fast