Counting Atoms

Front

What is the definition of an atom?

Back

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

Front

What is a compound?

Back

A compound is a substance formed when two or more different elements are chemically bonded together.

Front

How many atoms are in one molecule of water (H2O)?

Back

There are 3 atoms in one molecule of water: 2 hydrogen atoms and 1 oxygen atom.

Front

What does the subscript in a chemical formula indicate?

Back

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

Front

What is the total number of atoms in the compound H2SO4?

Back

There are 7 atoms in H2SO4: 2 hydrogen, 1 sulfur, and 4 oxygen.

Front

What is the difference between a coefficient and a subscript in a chemical equation?

Back

A coefficient indicates the number of molecules, while a subscript indicates the number of atoms in a molecule.

Front

What is the chemical formula for table salt?

Back

The chemical formula for table salt is NaCl.

Front

Is NaCl an element or a compound?

Back

NaCl is a compound.

Front

What is a physical change?

Back

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition.

Front

What is a chemical change?

Back

A chemical change is a change that results in the formation of new chemical substances.