How many atoms of lithium are in 2.5 moles

Determine the percent sulfuric acid by mass of a 1.61 m aqueous solution of h2so4. %

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.

Ab c or d ? i’m not sure what the answer is