Chapter 3: Matter

Matter

The material of the universe. It has mass and occupies space. Matter can undergo changes in both its physical and chemical properties.

Physical properties

• A characteristic of a substance that can change without the substance becoming a different substance.

• Typical physical properties of a substance include odor, color, volume, state, density, melting point, and boiling point.

Chemical properties

The ability of a substance to change to a different substance, which refers to its ability to form new substances.

Compounds

A substance with constant composition that can be broken down into elements by chemical processes. Example: water. Will always contain different elements.

Mixture

• A material of variable composition that contains two or more substances.

• Can be separated into pure substances (Although we say we can separate mixtures into pure substances, it is virtually impossible to separate mixtures into totally pure substances. Some impurities (components of the original mixture) remain in each of the “pure substances.”)

• Can be classified as homogeneous or heterogeneous

Pure substance

A substance with constant composition. The types of pure substances are elements and compounds.

Homogeneous mixture

A mixture that is the same throughout, aka solution

Solution

A homogenous mixture

Heterogeneous mixture

A mixture that has different properties in different regions of the mixture

Example: sand and water, water and oil, pizza.

Distillation

The method for separating the components of a liquid mixture that depends on differences in the ease of vaporization of the components

Filtration

A method for separating the components of a mixture containing a solid and a liquid

Elements

A substance that cannot be broken down into other substances by chemical means. There are 118 elements, and all of the matter in the world around us contains elements. More often they are combined with other elements. Each element is made up of a particular kind of atom.

Molecules

Any group of 2 or more atoms bonded together. Therefore, all compounds are molecules.