Elements, Compounds & Mixtures

Front

What is an element?

Back

An element is a pure substance that consists of only one type of atom. Examples include hydrogen (H), oxygen (O), and gold (Au).

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What is a compound?

Back

A compound is a substance formed when two or more different types of atoms bond together. Examples include water (H2O) and carbon dioxide (CO2).

Front

What is a mixture?

Back

A mixture is a combination of two or more substances that are not chemically bonded. Examples include air and salad.

Front

What is a molecule?

Back

A molecule is the smallest unit of a compound that retains the chemical properties of that compound. It consists of two or more atoms bonded together.

Front

What is an atom?

Back

An atom is the basic unit of matter and the smallest unit of an element. It consists of protons, neutrons, and electrons.

Front

What is the difference between a homogeneous mixture and a heterogeneous mixture?

Back

A homogeneous mixture has a uniform composition throughout (e.g., saltwater), while a heterogeneous mixture has a non-uniform composition (e.g., salad).

Front

Can an element exist as a molecule?

Back

Yes, some elements can exist as molecules, such as O2 (oxygen) and N2 (nitrogen), where two atoms of the same element bond together.

Front

What is an example of a heterogeneous mixture?

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An example of a heterogeneous mixture is uncooked chocolate chips and cookie dough blended together.

Front

What is the chemical formula for water?

Back

The chemical formula for water is H2O, which indicates it is made of two hydrogen atoms and one oxygen atom.

Front

What is the smallest unit of a compound?

Back

The smallest unit of a compound is a molecule.