States of Matter 7-5.10Compare physical changes (including changes in size, shape, and state) to chemical changes that are the result of chemical reactions (including changes in color or temperature and formation of a precipitate or gas).

States of Matter States of Matter- Different forms in which matter exist. Solid Liquid Gas When a substance changes from one state to another, the molecules in substance do not change. However, the arrangement of molecules does change, giving each state of matter its own characteristics.

Solid Substance that has a fixed volume and a fixed shape. In a solid that particles are close together and usually form a regular particle Particles in a solid can vibrate but are fixed in one place.

Liquid Fixed volume but does not have fixed shape. Liquids take on the shape of the container they are in. The particles in a liquid are attracted to one another and are close together. Particles in a liquid are not fixed in place and con move from one place to another.

Gas No fixed volume or shape. A gas can take on both shape and the volume of a container. Gas particles are not close to one another and can easily in any direction. There is much more space between gas particles than there is between particles in a liquid or a solid. The space between gas particles can increase or decrease with the changes in temperature and pressure.

Solids Cont’d Any matter that is a solid has definite shape and definite volume. Molecules in solids are in fixed positions and are tightly packed. The vibrates can still vibrate, but they can not move from one part of the solid to another. Solids do not easily change shape or volume. If you force the molecules apart, you can change the shape and volume by breaking it into pieces. Ex. Chopping wood

Liquids Cont’d Liquids have definite volume, but do not have a definite shape. You can measure the volume of a liquid, but the shape the liquid takes depends on the container it is in. The molecules in a liquid are close together, but they are not tightly attracted to one another as the molecules in a solid. This allows liquids to flow.

Gases Cont’d Gases have no volume and no definite shape. Gases have a volume that will change to match the volume of its container. Gas molecules are very far apart compared to liquids and solids. The amount of space between the molecules in a gas can change easily. If you add more oxygen to a tank, the volume of the gas does not change, but there is less space between the molecules.

Gas Behavior Gas molecules are constantly in motion, they are continually hitting one another and the sides of any container they may be in. As the molecules bounce off one another and the surfaces of the container, they apply a pressure against the container. Ex. Adding air to a bicycle tire The speed at which gas molecules move depends on the temperature. Gas molecules move faster at higher temperatures. The volume, pressure of a gas are related to one another.