The reaction rate or rate of reaction is the speed at which a chemical reaction takes place, defined as proportional to the increase in the concentration of a product per unit time and to the decrease in the concentration of a reactant per unit time.
Reactions that happen quickly have a high rate of reaction. For example, the chemical weathering of rocks is a very slow reaction: it has a low rate of reaction. Explosions are very fast reactions: they have a high rate of reaction. Rate of reaction is an example of a compound measure.
Answer: D) The effect of gravity on an object
Explanation: We're not talking about mass, we're talking about weight. Weight is measured by the force of gravity on a object. For examples, you might be 100 pounds on Earth but 12 pounds on the moon.
Greater rainfall has an greater increase on the rate of chemical weathering. Rain is a form of precipitation.
Simple...
moving along the periodic table ---->>>
Oxygen has 6.
Nitrogen has 5.
Sodium has 1.
Neon has 8.
Thus, your answer, Oxygen.