Chemistry the study of the properties of matter and how matter changes Matter – anything that has mass and occupies space. Substance – a single kind of matter that is pure. It has a specific composition and a specific set of properties. Examples: Table Salt, Table Sugar, and Baking Soda

Describing Matter Physical Properties - characteristics of a pure substance that can be observed without changing it into another substance. Examples: Change in Physical State, Texture, Color, Shape, Hardness, Flexibility, Luster, etc.

Physical Properties Some Examples:

Chemical Properties - a characteristic of a pure substance that describes its ability to change into different substances Flammability (Combustion) Ability to React (Oxidation/Tarnishing) New Substances, New Properties

Chemical Properties Some examples

Elements Element – a pure substance that cannot be broken down into any other substance by chemical or physical means. Elements are represented by one or two letter symbols such as C for carbon, H for hydrogen, Fe for iron, and Cu for copper.

Particles of Elements - Atoms Atom – the basic particle from which all elements are made.

When Atoms Combine Chemical bond – the force of attraction between two atoms. Molecules – groups of two or more atoms held together by chemical bonds.

Compounds Compound – a pure substance made of two or more elements chemically combined in a set ratio. Chemical formula – shows the elements in a compound and the ratio of atoms. Examples: H2O (water), NaCl (table salt) CO2 (carbon dioxide), and C12H22O11 (table sugar)

Mixtures Mixture – made of two or more substances that are together in the same place but are not chemically combined. Each substance in a mixture keeps its individual properties. Mixtures are not combined in a set ratio.

Heterogeneous Mixtures Heterogeneous mixture – a mixture in which you can see individual parts Examples:

Homogeneous Mixtures Homogeneous mixtures – a mixture that is so evenly mixed that you can’t see the different parts Examples:

Ways to Separate Mixtures Use a magnet Filter the mixture Use distillation Evaporation

Measuring Matter Mass - the amount of matter in an object Units: g or kg Volume - the amount of space matter occupies. Units: L, mL, and cm3 Density - the mass of a material in a given volume. (formula: mass/volume) Units are g/mL or g/cm3