Atoms, Elements, Molecules, Compounds

Front

What is an atom?

Back

The smallest unit of an element, consisting of protons, neutrons, and electrons.

Front

What is an element?

Back

A pure substance that cannot be broken down into simpler substances by chemical means, made up of only one type of atom.

Front

What is a molecule?

Back

A group of two or more atoms bonded together, which can be of the same or different elements.

Front

What is a compound?

Back

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

Front

Is water (H2O) a molecule or a compound?

Back

Water is both a molecule and a compound.

Front

What is the difference between a molecule and a compound?

Back

All compounds are molecules, but not all molecules are compounds. A molecule can consist of the same type of atoms.

Front

Give an example of a molecule that is not a compound.

Back

O2 (oxygen gas) is a molecule made of two oxygen atoms, but it is not a compound.

Front

What does it mean for a substance to be chemically bonded?

Back

It means that atoms are held together by chemical forces, forming a new substance.

Front

What is the chemical formula for carbon dioxide?

Back

CO2, which consists of one carbon atom and two oxygen atoms.

Front

What is the significance of the subscript in a chemical formula?

Back

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