What is a mixture that appears to contain only one substance

Consider the nuclear equation below. 239/94 pu—-> x+ 4/2 he. what is x?

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.

What happened to the amount of carbon dioxide in the atmosphere from 2010–2017?