Nitrogen-13 emits beta radiation and decays to carbon-13 with a half life of 10 min. Assume a starting mass of 4.00 g of nitrogen -13. How much would remain
after 30 min.?*

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.

Electric charge is what ? a. kinetic energy b. radiation c. discovery d. electricity

Which of the following substances is the most soluble in water? a. sodium chloride b. methane c. bromine d. carbon