The chemical formula for burning methane gas is CH₄ + 2O₂ → CO₂ + 2H₂O. How many atoms of oxygen are present in the reactants?

• 2

• 4

• 6

• 8

In the reaction 4Fe + 3O2 → 2Fe2O3, the coefficient of iron (Fe) is ___.

What is the total number of hydrogen atoms in the products of the methane combustion reaction?

• 2

• 4

• 6

• 8

The periodic table is arranged in order of increasing atomic number, which is the number of ___.

In a chemical equation, the substances on the left side are called ___.

Which of the following is a product in the reaction CH4 + 2O2 → CO2 + 2H2O?

• CH4

• O2

• CO2

• Fe

In the reaction 4Fe + 3O2 → 2Fe2O3, how many molecules of Fe2O3 are produced?

• 1

• 2

• 3

• 4