Which of the first four radioisotopes in the decay series has the longest half-life? Pa-234

Th-234

U-234

U-238

Which statement best describes the relationship between period and frequency of light waves? a) in wave b the period increases and the frequency decreases from wave a. b) in wave a the period increases and the frequency decreases from wave b. c) in wave b the period is shorter and the frequency is greater than in wave a. d) in wave a the period is shorter and the frequency is greater than in wave b.

Which of the following electromagnetic waves can create ions?

How many grams of co(g) are there in 74.5 ml of the gas at 0.933 atm and 30o c?