Which statement refers to convection? Sunlight travels through space without the aid of fluids or solids.

Land and ocean absorb and re-emit heat from the sun.

Some of this energy is reflected off Earth's atmosphere.

Warm air rises and takes heat with it; eventually it cools and sinks.

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.