2.6 - Elements, Compounds and Mixtures

An element is a pure substance that cannot be broken down into simpler substances by chemical means. It consists of only one type of atom.

A compound is a substance formed when two or more elements chemically bond together in fixed proportions.

A mixture is a combination of two or more substances that are not chemically bonded and can be separated by physical means.

An atom is the smallest unit of a chemical element that retains its chemical properties.

A molecule is a group of two or more atoms bonded together, which can be of the same or different elements.

A homogeneous mixture is a mixture that has a uniform composition and appearance throughout, such as saltwater.

A heterogeneous mixture is a mixture that has a non-uniform composition, where the different components can be seen, such as a salad.

A solution is a homogeneous mixture where one substance (the solute) is dissolved in another (the solvent), such as sugar in water.

When elements form a compound, chemical bonds are created between the atoms of the elements.

A compound is made of two or more elements chemically bonded together, while a mixture consists of two or more substances that are not chemically bonded.