1.2 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 (O), hydrogen (H), and gold (Au).

Front

What is a compound?

Back

A compound is a substance formed when two or more elements chemically bond 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 combined. Examples include air (a mixture of gases) and salad (a mixture of vegetables).

Front

How can you identify a mixture?

Back

A mixture can be identified by the fact that its components retain their individual properties and can often be separated by physical means.

Front

What is the difference between a compound and a mixture?

Back

A compound is made of two or more elements that are chemically bonded, while a mixture consists of substances that are physically combined and can be separated.

Front

What happens when elements combine chemically?

Back

When elements combine chemically, they form a compound with new properties that are different from the individual elements.

Front

What is rust?

Back

Rust is a compound formed when iron reacts with oxygen in the presence of water or moisture, resulting in iron oxide (Fe2O3).

Front

Can a mixture be homogeneous?

Back

Yes, a homogeneous mixture has a uniform composition throughout, such as saltwater, where the salt is evenly dissolved.

Front

Can a mixture be heterogeneous?

Back

Yes, a heterogeneous mixture has a non-uniform composition, such as a salad, where the individual ingredients can be seen and separated.

Front

What is an example of a compound?

Back

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