When constructing a conversion factor to use in a stoichiometry problems, what numbers are used? a) coefficients from the balanced equations.
B) subscripts from the chemical formulas

a. a primary source combines several different accounts of an event. b. a primary source generally benefits from having been written after an event.

explanation:

plants need sunlight, water, and carbon dioxide to make food. plants use the raw materials of water, nutrients they absorb from soil, and carbon dioxide to make sugars the plant can use. energy from the sun and chlorophyll are also needed.

gas

explanation:

smoke is the matter of a gas

a is the correct answer