Which statement about enzymes is true?

a)they are large molecules that decrease the rate of reactions in the body.
b)they are large molecules that increase the rate of biologically important reactions.
c)they slow the rate of chemical reactions.
d)they are permanently changed in the course of a reaction.

Base your answer on the information below and on your knowledge of chemistry. nitrogen dioxide, no2, is a dark brown gas that is used to make nitric acid and to bleach flour. nitrogen dioxide has a boiling point of 294 k at 101.3 kpa. in a rigid cylinder with a movable piston, nitrogen dioxide can be in equilibrium with colorless dinitrogen tetroxide, n2o4. this equilibrium is represented by the equation below. 2no2(g) n2o4(g) + 58kj at standard pressure, compare the strength of intermolecular forces in no2(g) to the strength of intermolecular forces in n2(g).

Which statement is best described as a atom

What happens to isotopes that are unstable?