Chemistry Matter and Change

Chemistry is… …the study of the composition, structure, and properties of matter and the changes it undergoes C2H5OH + 3 O2  2 CO2 + 3 H2O + Energy Reactants  Products

Matter Mass Volume Anything that has mass and occupies space A measure of the amount of matter Volume A measure of the space the object occupies

Physical Change A change in a substance that does not involve a change in the identity of the substance. Example: Phase Changes

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.

Three Phases

Copper Phases - Solid

Copper Phases - Liquid

Copper Phases – Vapor (gas)

Chemical Change A change in which one or more substances are converted into different substances. Heat and light are often evidence of a chemical change.

Properties of Matter Physical Property Chemical Property A property that can be determined without changing the nature of the substance. Examples Melting Point and Boiling Point Color Density Chemical Property A property of matter that describes a substance’s ability to participate in chemical reactions. Examples Reactivity (with oxygen-rust) Heat of Combustion Flammability

Density The ratio of the mass of a substance to the volume of the substance

Atom Pure Substance Element The smallest unit of an element that maintains the properties of that element Pure Substance A sample of matter, either a single element or a single compound, that has definite chemical and physical properties Element A pure substance made of only one kind of atom

Molecule The smallest unit of substance that keeps all of the physical and chemical properties of that substance Usually consists of two or more atoms combined in a definite ratio Oxygen Gas O2 Colorless, order less, essential to most life forms Ozone O3 Toxic, sharp odor, pale blue gas Just one type of atom

Compound A substance that is made from the atoms of two or more elements that are chemically bonded. Sucrose – C12H22O11 Sucrose is also known as table sugar, and is used to make Gummy Bears!

Mixtures Homogeneous Heterogeneous A combination of two or more substances that are not chemically combined Homogeneous Describes something that has a uniform structure or composition throughout Heterogeneous Composed of dissimilar components

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

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

Separation of a Mixture Distillation

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 H2O  H2 + O2

Classification of Matter

The Periodic Table Period Group or Family Group or family Period