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).

Front

What is a compound?

Back

A compound is a substance formed when two or more elements are chemically bonded together. An example is water (H2O), which is made of hydrogen and oxygen.

Front

What is a mixture?

Back

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

Front

What distinguishes a homogeneous mixture from a heterogeneous mixture?

Back

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

Front

What is the chemical formula for table salt?

Back

The chemical formula for table salt is NaCl, which indicates it is a compound made of sodium (Na) and chlorine (Cl).

Front

Can elements be broken down into simpler substances?

Back

No, elements cannot be broken down into simpler substances by chemical means.

Front

What is the difference between a physical change and a chemical change?

Back

A physical change alters the form of a substance but not its chemical composition (like melting ice), while a chemical change results in the formation of new substances (like rusting iron).

Front

What is an example of a compound?

Back

An example of a compound is carbon dioxide (CO2), which consists of carbon and oxygen.

Front

What is an example of a heterogeneous mixture?

Back

An example of a heterogeneous mixture is a bowl of cereal with milk, where the components can be seen and separated.

Front

What is the process of combining elements to form a compound called?

Back

The process of combining elements to form a compound is called chemical bonding.