Counting Atoms

Front

What is a chemical formula?

Back

A chemical formula is a way of expressing the number and type of atoms in a molecule using symbols and numbers.

Front

How do you count atoms in a chemical formula?

Back

Count the number of each type of atom represented by the symbols in the formula, using the subscript numbers to indicate quantity.

Front

What does the subscript in a chemical formula indicate?

Back

The subscript indicates the number of atoms of the element that are present in the molecule.

Front

What is the chemical formula for three hydrogen (H), one sulfur (S), and four oxygen (O) atoms?

Back

H₃SO₄

Front

How many carbon atoms are in the formula 2Na₂CO₃?

Back

There are 2 carbon atoms.

Front

How many oxygen atoms are in the compound H₂O?

Back

There are 1 oxygen atom.

Front

In the compound H₂C₃O₄N₅, how many carbon atoms are present?

Back

There are 3 carbon atoms.

Front

What is the chemical formula for two aluminum nitride molecules?

Back

2AlN contains 2 nitrogen atoms.

Front

What is the significance of coefficients in a chemical formula?

Back

Coefficients indicate how many molecules of the compound are present.

Front

What is the difference between an atom and a molecule?

Back

An atom is the smallest unit of an element, while a molecule is a group of two or more atoms bonded together.