1. Jenny L, Ericka P, Taelyr S.

2. The salinity of sea water (usually 3.5%) is made up by dissolved salts. Their proportions are always the same, which can be understood if salinity differences are caused by either evaporating fresh water or adding fresh water from rivers.

3. Water vapor rises from the ocean surface through evaporation and is carried landward by the winds in the form of clouds and humidity. When the vapor in the clouds collides with a colder mass of air, the moisture condenses (changes from a gas to a liquid) and falls to Earth as rain. The rain runs off into streams, or underground as groundwater, both of which transport water back to the sea. Evaporation from both the land and the ocean again causes water to return to the atmosphere as vapor and the cycle starts anew.

4. Gases of the atmosphere, mostly Oxygen(02) Carbon Dioxide(CO2), and Nitrogen(N2), are also found in seawater. These gases dissolve at the surface of the sea and are distributed throughout the water by mixing processes and currents. Carbon Dioxide and Oxygen play important roles in the lives of marine organisms.