Matter and Changes Matter - anything that has mass and takes up space. Mass - the measurement of the amount of matter in an object. We use a balance to determine mass. The amount of space is a volume measurement

Four states of matter: Solid - anything that has both a definite volume and a definite shape. Liquid - anything that has definite volume but no definite shape - flows and can be poured. Gas - has no definite volume and no definite shape.  always takes volume and shape of container if not in container, it will spread as far as can. Plasma - has no definite volume or shape - composed of electrical charged particles.

Characteristics of matter Atoms are small particles that make up matter. A pure substance that is made of only one kind of atom is called an element. Most elements are found combined together as molecules rather than individual atoms. Elements in their pure state are difficult to find because they usually react to form compounds, a substance that is composed of molecules containing more than one element.

Flow Chart Of Matter MATTER MIXTURE PURE SUBSTANCE HOMOGENEOUS physical change PURE SUBSTANCE HOMOGENEOUS HETEROGENEOUS solutions chemical change ELEMENT COMPOUND

Physical Changes One important characteristic of compounds is that they cannot be separated into atoms they are made of by physical methods. Physical methods include: freezing, boiling, straining, filtering, or even dissolving in water. Water, for example, can be frozen or boiled, but the ice or water vapor is still water!  Freezing and boiling cannot separate water molecules into hydrogen and oxygen atoms.

Most matter is not pure but is made of a combination of molecules of two or more different substances.  A mixture is the combination of different molecules that are not chemically combined. The key characteristic of a mixture is that each of the different kinds of molecules in the mixture keeps its own identity.

You can take a mixture apart, and separate the different molecules of the mixed substances. Unlike compounds, mixtures can be separated into their parts using physical methods. Filtration Evaporation Chromatography Distillation

Properties of matter A substance may be identified by certain qualities, or traits - a quality or trait that identifies a substance is called a property. The properties of a substance stays the same even if its volume changes. Color, mass, small, density, and composition are all examples of properties that can help scientist identify substances.

Every substance has two kinds of properties - physical properties and chemical properties. A physical property is a property of matter that can be observed or measured without changing the composition of the substance. Physical properties are often used to identify substances.

Some physical properties of matter Boiling point - the temperature at which a substance changes from a liquid to a gas. Condensation point - the temperature at which a substance changes from a gas to liquid; same temperature as boiling point. Freezing point - the temperature at which a substance changes from a liquid to a solid;  same temperature as melting point. Melting point - the temperature at which a substance changes from a solid to a liquid.

Some physical properties of matter Density - the mass of a specific volume of substance. Resistance - the ability of a substance to slow down the flow of electric current. Solubility - the degree to which a substance will dissolve in a given amount of another substance, such as water.

Physical changes A physical change is a change that does not produce a new kind of matter. When you stretch a rubber band or crush a cube of ice, you are causing physical change. Only certain physical characteristics of matter, such as shape, and volume, are changed.

Common physical changes include phase changes such as freezing, melting and boiling. All pure substances can change from phase to phase without changing their chemical composition. When a liquid freezes, it changes from a liquid phase to a solid phase. The temperature at which a substance changes from a liquid to a solid is called its freezing point.

Water for an example, turns to ice at its freezing point Water for an example, turns to ice at its freezing point. If the ice is heated, it changes back to a liquid. The temperature at which a substance changes from a solid to a liquid is called its melting point.

Condensation is the changing of phases from a gas to a liquid Condensation is the changing of phases from a gas to a liquid. Condensation is the opposite of boiling. If water is then boiled, it changes from a liquid phase to a gaseous phase. Evaporation is the opposite of condensation. A liquid changes to a gas and moves into the surrounding atmosphere. Sublimation is a phase change in which a solid changes directly into a gas. Dry ice is an example of a substance that sublimes.

Phase changes are related to temperature Phase changes are related to temperature.  If you have a colorless liquid that boils at 100 degrees C and freezes at 0 degrees C, you can be reasonably certain the substance is ______________.

What is a chemical change? Chemical changes are changes substances undergo when they become new or different substances. For example, the fireworks we see on the 4th of July are actually metals such as magnesium and copper that change chemically - they light up the night skies with their fantastic colors.

To identify a chemical change look for observable signs such as: Color change Bubbling and fizzing Light production Smoke Presence of heat or cold