Elements, Compounds and Mixtures

Front

What is an element?

Back

An element is a pure substance that cannot be broken down into simpler substances by chemical means. Examples include oxygen, hydrogen, and gold.

Front

What is a compound?

Back

A compound is a substance formed when two or more elements chemically 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, salad, and saltwater.

Front

What distinguishes a pure substance from a mixture?

Back

A pure substance has a uniform and definite composition, while a mixture contains two or more substances that retain their individual properties.

Front

What is an example of a homogeneous mixture?

Back

A homogeneous mixture is a mixture that has a uniform composition throughout, such as saltwater or air.

Front

What is an example of a heterogeneous mixture?

Back

A heterogeneous mixture is a mixture that does not have a uniform composition, such as a salad or a bowl of mixed nuts.

Front

What happens when sugar dissolves in water?

Back

When sugar dissolves in water, it forms a mixture where the sugar molecules are evenly distributed throughout the water.

Front

Why is oxygen classified as a pure substance?

Back

Oxygen is classified as a pure substance because it consists of only one type of atom and does not contain any other substances.

Front

What is rust, and how is it classified?

Back

Rust is a compound formed when iron reacts with oxygen in the presence of moisture. It is classified as a compound.

Front

What is the chemical formula for water?

Back

The chemical formula for water is H2O, indicating it is a compound made of two hydrogen atoms and one oxygen atom.