Coefficients are used here to balance the number of elements in the products and reactants. Coefficients are numbers that are placed in front of a chemical formulas in an equation. Hope it's useful.
A. Coal produces the most carbon dioxide. The answer is A.
A coffee filter, a strainer, or a ladle can be used to separate the parts of a heterogeneous mixture.
Matter is made up of particles too small to be seen with the naked eye called atoms
Answer:

Explanation:
When a chemical change happens or chemical reaction happens something yields at reactants and something at products
Representing them is called chemical equation