Counting Atoms

Front

What is a coefficient in a chemical formula?

Back

A coefficient is a number placed in front of a chemical formula that indicates how many molecules or atoms of that substance are present. It multiplies all the atoms in the formula.

Front

How do you calculate the total number of atoms in a chemical formula?

Back

To find the total number of atoms, add up the number of each type of atom present in the formula, taking into account any coefficients and subscripts.

Front

What does the subscript in a chemical formula represent?

Back

A subscript indicates the number of atoms of the element that are present in one molecule of the compound.

Front

How many atoms are in H₂SO₄?

Back

There are 7 atoms in total: 2 Hydrogen (H), 1 Sulfur (S), and 4 Oxygen (O).

Front

What is the total number of Sodium (Na) atoms in 6NaCl?

Back

There are 6 Sodium (Na) atoms.

Front

How many Oxygen (O) atoms are in Al₂(SO₄)₃?

Back

There are 12 Oxygen (O) atoms.

Front

What elements are represented in the chemical formula Fe₂O₃?

Back

The elements represented are Iron (Fe) and Oxygen (O).

Front

What is the purpose of parentheses in chemical formulas?

Back

Parentheses are used to group atoms together, indicating that the atoms inside the parentheses are multiplied by the subscript outside.

Front

How do you determine the number of atoms in a compound with parentheses?

Back

Multiply the subscript outside the parentheses by each subscript inside the parentheses to find the total number of each type of atom.

Front

What is the difference between a coefficient and a subscript?

Back

A coefficient applies to the entire formula and indicates how many molecules are present, while a subscript applies only to the element it follows and indicates how many atoms of that element are in one molecule.