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 hydrogen, oxygen, and gold.

Front

What is a compound?

Back

A compound is a substance formed when two or more elements are chemically bonded 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 retain their individual properties. Mixtures can be homogeneous or heterogeneous.

Front

What is a homogeneous mixture?

Back

A homogeneous mixture is a mixture that has a uniform composition throughout. Examples include saltwater and air.

Front

What is a heterogeneous mixture?

Back

A heterogeneous mixture is a mixture that does not have a uniform composition and the individual substances can be seen. Examples include salad and sand.

Front

What is the difference between a pure substance and a mixture?

Back

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

Front

What happens when electricity passes through water?

Back

When electricity passes through water, it undergoes electrolysis, breaking down into hydrogen and oxygen gases.

Front

What is an example of a pure substance?

Back

An example of a pure substance is helium gas in a balloon, as it consists of only one type of particle.

Front

Why is saltwater considered a mixture?

Back

Saltwater is considered a mixture because it is composed of two substances (salt and water) that retain their own chemical properties.

Front

What is the chemical formula for water?

Back

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