Counting Atoms

Front

What is an atom?

Back

An atom is the smallest unit of matter that retains the properties of an element.

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

In the formula C6H12O6, how many carbon atoms are there?

Back

6 carbon atoms.

Front

In the formula C3H5(NO3)3, how many nitrogen atoms are there?

Back

3 nitrogen atoms.

Front

What does the subscript in a chemical formula indicate?

Back

The subscript indicates the number of atoms of the element in the molecule.

Front

How many total atoms are in the formula C6H12O6?

Back

24 total atoms (6 C + 12 H + 6 O).

Front

What is the significance of parentheses in a chemical formula?

Back

Parentheses indicate that the atoms inside are grouped together and the subscript outside applies to all atoms within the parentheses.

Front

How many hydrogen atoms are in the compound H2O?

Back

2 hydrogen atoms.

Front

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

Back

H3SO4.

Front

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

Back

Count the number of O's in the chemical formula, including any subscripts.