The Earth's atmosphere is made up of approximately

__

% nitrogen.

A. 1

B. 21

C. 78

D. none of the above

What is locked up carbon dioxide

Which statement is true about the proteins found in different organisms? The proteins of different organisms are different, but they are all made of the same set of 20 different parts. The same proteins are found in all different organisms.

Choose the products that complete the reaction. The chemical equation may not be balanced. NaHCO3 + HC2H3O2 a. NaC2H3O2 + H2O b. NaC2H3O2 + CO2 + H2O c. NaC2H3O2 + H2

The main function of the circulatory system (at least a paragraph) !

Which of the following is able to respond to its environment? A. air B. fire C. fish D. water

A diatomic gas has the molar mass of 38.00g/mol. what is the possible formula?

Which of the following is the final concentration of KCl if 500 ml of 0.25 M KCl is diluted to a final volume of 5 L? 0.025 L 0.0025 L 25 L 2.5 L

What do you use to measure mass

A salt shaker filled with 17.0g sodium chloride contain how many moles?

When a radioactive decay occurs what is released? A. Only protons and neutrons B. Only electrons C. Protons/Neutrons, beta particle, gamma ray D. Only gamma rays