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 substance 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, considering any subscripts.

Front

What does a subscript in a chemical formula indicate?

Back

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

Front

In the formula H₂O, how many hydrogen atoms are there?

Back

There are 2 hydrogen atoms in the formula H₂O.

Front

In the formula CaCl₇, how many chlorine atoms are there?

Back

There are 7 chlorine atoms in the formula CaCl₇.

Front

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

Back

There are 6 total atoms in the formula 2H₂O (2 H atoms and 1 O atom per molecule, multiplied by 2).

Front

How many atoms of Carbon (C) are in the formula 3C₂HAu₅?

Back

There are 6 Carbon atoms in the formula 3C₂HAu₅.

Front

What is the significance of coefficients in a chemical equation?

Back

Coefficients indicate the number of molecules or moles of a substance in a chemical reaction.

Front

In the formula HFe₅Cl, how many iron atoms are there?

Back

There is 1 iron atom in the formula HFe₅Cl.