Which event was responsible for supplying the early earth with water

Can someone me with 1 to 4 plz. fast

In a ni-cd battery, a fully charged cell is composed of nickelic hydroxide. nickel is an element that has multiple oxidation states. assume the following proportions of the states: nickel charge proportions found 0 0.17 +2 0.3 +3 0.33 +4 0.5 (a) determine the mean of the nickel charge. enter the answer to 2 decimal places.(b) determine the cumulative distribution function of nickel charge.

What happens to the concentration of hydronium ions as the ph of a solution increases? a. hydronium ion concentration stays the same b. hydronium ion concentration decreases c. hydronium ion concentration increases