Classification of Matter 1. Composition of Matter 2. Properties of Matter

Composition of Matter Matter takes up space and is composed of particles and of various substance. Particles = Atoms + Molecules Substance can either be pure or impure.

Substance - Pure Element – When all atoms in a substance are alike, the substance is called element. Example: Gold, Copper, Lead, etc… Compound – is a substance with two or more elements combined by chemical means, and in a fixed proportion. Example: Water, Salt, Chalk, OTC pills, etc…

Substance - Impure Mixture – Two or more substances that can be easily separated by physical means. Two types of mixtures: Heterogeneous mixture Homogeneous mixture (solution)

Mixtures Heterogeneous – mixture of different and easily distinguishable materials. Example: Granite rock (mica, quartz, microcline), Permanent press fabric, Homogeneous – mixture of two or more gaseous, liquid, or solid substances blended evenly; also called a solution. Example: Vinegar, Soda, Air, Contact Lens Saline, Toothpaste

Heterogeneous Mixtures Two types: Colloid Suspension Colloid: Heterogeneous mixture with large particles that never settle. Example: fog, gelatin, paint Suspension: Heterogeneous mixture containing a liquid in which visible particles settle. – Example: Pond, Cells in test tube.

Physical Property Characteristics of a material which can be observed without changing the identity of the substance Appearance – e.g. color, shape, size Behavior – viscosity, magnetism, ductility Understanding these properties allow you to separate them from a mixture.

Physical Change Change in a substance’s size, shape, or state of matter Substance does NOT change identity Reversible process Examples: Dissolving salt in water; Denting a car bumper; water to ice or vapor; Glass break Ice cream melts

Chemical Properties Characteristics of a substance indicating that it can change chemically. Example: Flammability of a substance Light sensitivity of a substance

Chemical Change When one substance change to another substance Allows us to separate substance such as metals from their ores. Indicators: Temperature: change in smell, bubble formation Color Change: Rusting Examples: Burning candle, Cooking Food Digestion Photosynthesis

Weathering Earth’s surface involve both physical and chemical changes. Physical – Big rocks split into smaller ones; stream carry rock particles from one location to another. Chemical – occurs in rocks when calcium carbonate in limestone changes to calcium hydrogen carbonate due to acid rain.

Law of Conservation of Mass Mass of all substances present before a chemical change equals the mass of all substances after the change.