Which term describes free-floating, photosynthetic microorganisms in the oceans that are important for producing oxygen? A. phytoplankton B. yeasts C. pathogens D. protozoa

Which of the following elements in the third period would you expect to have the most negative electron affinity value, and why?

A gas is confined in a steel tank with a volume og 6.982L at 20.20c the gas exerts a pressure of 8.532 atm. after heating the tank the pressure of gas increases to 10.406atm. what is the temperature of the heated gas convert celsius temp to kelvins

What is the mass, in grams, of a sample of 6.12 * 10^24 atoms of manganese (Mn) ? Show your work or explain the steps that you used to determine your answer.

Does earth have a retrograde rotation

Baking soda and vinegar can be used to model a volcanic eruption in a science demonstration because they bubble violently when mixed. What can be concluded about mixing vinegar and baking soda? Baking soda and vinegar make a uniform mixture.

Why is photosynthesis so important to plants, and can't animals use it?

One way the government of Kim Jong-il controls the lives of the people who live in North Korea is by a. requiring every citizen to vote. b. controlling information its people receive from the outside world. c. enforcing free trade with other nations.

Give reasons 1) copper utensils and sheets become blackish after some days

Predict the spontaneity of a reaction (and the temperature dependence of the spontaneity) for each possible combination of signs for? H and? S (for the system).

At 29°C, Kp = 5.3 ✕ 102 atm-2 for the following reaction. N2 (g) + 3 H2 (g) equilibrium reaction arrow 2 NH3 (g) When a certain partial pressure of NH3 (g) is put into an otherwise empty rigid vessel at 29°C, equilibrium is reached when 55.