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.

Front

Identify the number of elements in the formula CO2H5.

Back

There are 3 elements: Carbon (C), Oxygen (O), and Hydrogen (H).

Front

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

Back

Add the subscripts of each element, multiplied by the coefficient if present.

Front

What does the subscript in a chemical formula represent?

Back

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

Front

In the formula 3C2HAu5, how many total atoms of Carbon (C) are there?

Back

There are 6 total atoms of Carbon (C).

Front

How many atoms of Calcium (Ca) are in the formula H3O5CaCl7?

Back

There is 1 atom of Calcium (Ca).

Front

What is the total number of atoms in the formula 2H2O?

Back

There are 6 total atoms in 2H2O.

Front

What is the significance of the number in front of a chemical formula?

Back

It indicates how many molecules of that compound are present.

Front

How many total atoms are in the formula 4NaCl?

Back

There are 8 total atoms (4 Sodium (Na) + 4 Chlorine (Cl)).

Front

What does the formula H2O represent?

Back

H2O represents water, consisting of 2 Hydrogen (H) atoms and 1 Oxygen (O) atom.