Whitch of these is not a challenge an organism encounters

What is the relation between concentration of reactants and the rate of chemical reaction?

The characteristic of two different types of reactions are shown below. reaction a: electrons are gained by the atoms of an element. reaction b: protons are lost by the atom of and element. which statement is true about the atoms of the elements that participate in the two reactions? a: their identity changes in both reaction a and b. b: their identity changes in reaction a but not b. c: their identity changes in reaction b but not a. d: their identity remains the same.

At 300 mm hg, a gas has a volume of 380 l, what is the volume at standard pressure