Please help ? What is NOT true of a reaction that is at equilibrium

CO(g)+2H2(g)<——->CH3 OH(g)

A. It is a symbolized by a double<—> arrow symbol

B. The rate of the forward and reverse reactions are equal

C. The concentrations of products and reactants are equal

D. There is no net change in the concentration of the reactants or products the concentration of reactants and products are constant

Which best describes how johannes kepler developed his laws of planetary motion

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.

6. using 3 – 4 sentences explain (in your own words) why water expands when it freezes? 7. using your knowledge of colligative properties explain whether sodium chloride or calcium chloride would be a more effective substance to melt the ice on a slick sidewalk. use 3 – 4 sentences in your explanation.