How many hydrogen ions (H+) are in a mole ?

please show your solutions. thank you​

What is the chemical formula of the following compound

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.

Stage in which a typical star has completely stopped fusion