How can we know that atoms exist and understand them is they are visible?

7. what temperature is need to just dissolve 50 g of nh4cl in 75 g of water? '

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.

Light waves are as they pass through the