MATTER

Objects that take up space and have mass are called matter. WHAT IS MATTER? Objects that take up space and have mass are called matter. Everything around you is made up of matter.

STATES OF MATTER Most matter on earth can exist in three states. Solid- particles are packed together and cannot move. Liquid- particles are close together but they are not held together as tight as in q solid. Particles can move and slide past each other. Gas- particles are moving so fast that they don’t even stay close together. Gases expand to fill all the space available.

Solid- has a definite shape and volume Liquid- no definite shape but has definite volume. Takes the shape of the container it is in. Gas- Has no definite shape or volume

PHASE CHANGES Matter can change from one state to another when thermal energy is absorbed or released.

SOLID-LIQUID CHANGES OF STATE Melting: The change of state from a solid to a liquid. Melting occurs when a solid absorbs thermal energy. Melting point: Temperature at which solid becomes a liquid. Freezing: The change of state from a liquid to a solid. Freezing occurs when matter releases thermal energy. Freezing point: The temperature at which liquid becomes a solid.

LIQUID-GAS CHANGES OF STATE Vaporization- process in which matter changes from a liquid to a gas. Evaporation- vaporization taking place at the surface of a liquid. Boiling: vaporization taking place below the surface of a liquid. Boiling point- Temperature at which a liquid becomes a gas.

PROPERTIES OF MATTER

Physical properties: -Outward observable characteristics of matter, which include: -color -size/shape -smell -texture -mass -weight -volume -density

Chemical properties: How matter changes into other new matter Flammability: ability of an object to burn. Reactivity: ability to react with other matter.

PHYSICAL CHANGES AND CHEMICAL CHANGES

PHYSICAL CHANGES A physical change does not produce a new substance. Changes in state or phase (melting, freezing, vaporization, condensation, sublimation) are physical changes. Examples of physical changes include crushing a can, melting an ice cube, and breaking a bottle.

CHEMICAL CHANGES Chemical changes take place on the molecular level (when the molecules change). A chemical change produces a new substance. Examples of chemical changes include combustion (burning), cooking an egg, and rusting of an iron pan

How to Tell Chemical & Physical Changes Apart A chemical change makes a substance that wasn't there before. There may be clues that a chemical reaction took place, such as light, heat, color change, gas production, odor, or sound. The starting and ending materials of a physical change are the same, even though they may look different.