The Organization of Matter Mixtures: a) Homogeneous (Solutions) b) Heterogeneous Pure Substances Elements Compounds Atoms Nucleus Electrons Protons Neutrons Quarks Quarks

Matter: Anything occupying space and having mass. Copyright©2000 by Houghton Mifflin Company. All rights reserved.

Properties of matter Property – any characteristic that allows us to recognize a particular type of matter and to distinguish it from other types of matter Each substance has a unique set of physical and chemical properties.

Properties of Matter Extensive properties depend on the amount of matter that is present. Volume Mass Energy Content (think Calories!) Intensive properties do not depend on the amount of matter present. Melting point Boiling point Density

Properties of matter Physical Properties Physical Properties are measured without changing the substance. e.g., color, density, odor, melting point Chemical Properties Chemical Properties describe how substances react or change to form different substances e.g., rusting of an iron nail at room temperature, sodium reacts violently with water, radioactive decay, lack of reactivity

Phase Differences Solid – definite volume and shape; particles packed in fixed positions. Liquid – definite volume but indefinite shape; particles close together but not in fixed positions Gas – neither definite volume nor definite shape; particles are at great distances from one another Plasma – high temperature, ionized phase of matter as found on the sun.

Classifying Matter: Types of Mixtures Mixtures have variable composition. A homogeneous mixture is a solution (for example, vinegar) A heterogeneous mixture is, to the naked eye, clearly not uniform (for example, a bottle of ranch dressing) Copyright©2000 by Houghton Mifflin Company. All rights reserved.

Separation of a Mixture The constituents of the mixture retain their identity and may be separated by physical means.

Pure Substances Can be isolated by separation methods:  Chromatography  Filtration  Distillation Copyright©2000 by Houghton Mifflin Company. All rights reserved.

Separation of a Mixture The components of dyes such as ink may be separated by paper chromatography.

Separation of a Mixture by Distillation

Classifying Matter: Types of Substances Compound: A substance with a constant composition that can be broken down into elements by chemical processes. Element: A substance that cannot be decomposed into simpler substances by chemical means.

Separation of a Compound The Electrolysis of water Compounds must be separated by chemical means. With the application of electricity, water can be separated into its elements Reactant  Products Water  Hydrogen + Oxygen 2 H2O  2 H2 + O2