How are you finding the moles of the unknown substance when you are only given the grams of the unknown molecular compound?

What is the value of keq for the reaction expressed in scientific notation

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.

Name the element in group 17, period 2. (periodic table)