Matter All matter has Mass and Volume. Every sample of matter is either an element, a compound, or a mixture.

Element A substance that cannot be broken down into simpler substances by chemical means.

Atoms Each element is made of one kind of atom. Atoms are the smallest unit of an element that maintains the chemical properties of that element.

Symbols Short hand way of writing element names. First letter capital. All others are lower case. One, two or three letters. Print like in kindergarten.

Elements of the Human Body In order of amounts Oxygen about 66% of body. Carbon about 18%. Hydrogen about 10%. Potassium, calcium, sulfur,nitrogen, phosphorus, sodium 2% or less.

Molecule Smallest unit of substance that behaves like the substance. Examples H2O, O2

Compounds Substance made up of atoms of different elements. Each molecule of a compound contains 2 or more elements that are chemically combined. They combine in the same proportions. Example- NaCl, KOH

Compounds Have unique properties Have properties unlike elements that combine to make the compound.

Chemical Formula Shows how many atoms of each element make up the compound The number of atoms is written as a subscript after the element’s symbol. If only one atom, then no subscript. NO, NO ones. Numbers in front of compound show molecules. Example 3H2O

Pure Substances Pure substance- matter that has a fixed composition. Elements and compounds are pure substances. Pure substances can not be separated into parts. They are chemically combined and can not be physically separated.

Mixtures Combination of substances that are not chemically combined Can be separated into their parts Classified by how well they mix

Types of Mixtures Homogeneous Mixture Heterogeneous Mixture

Homogeneous Mixture Components are evenly distributed Mixture is the same throughout Can also be called a solution. Example- gasoline-100 liquids Gasoline is misicible. Miscible- able to be mixed. Immiscible-will not mix Example- oil and water

Heterogeneous Mixture Substances not evenly distributed Some are hard to recognize. Ex. Shirt- cotton and polyester salad

Miscible and Immiscible Gasoline is miscible. Miscible- able to be mixed. Immiscible-will not mix Example- oil and water Gases can mix with liquids. Gas-liquid mixture- carbonated drinks gas in drink and air bubbles foam egg whites

Properties of Matter Physical properties Chemical properties

Physical Properties Characterists that can be observed without changing the identity of the substance Can help identify substances state, color Can be observed and measured boiling point- the temp at which a liquid changes to a gas melting point-the temp at which a solid changes to a liquid Help determine uses-antifreeze, aluminum foil Example-strength, hardness, magnetism, ability to conduct heat or electricity, density

Density D=m/v Measure of how much matter is contained in a certain volume of a substance Units- example- g/cm3, g/ml, cg/ml Water has a density of 1g/cm3 A cubic centimeter has the same volume as a milliliter.

Density, Mass, Weight Density is different from Mass. Mass and weight are different. D= mass/volume Mass- amount of substance Weight- pull of gravity on a substance.

Chemical Properties Describes how a substance changes into a new substance, by 1. combining with other elements 2. breaking apart into new substances Example- 1. Flammability – ability to burn 2. Nonflammability-does not burn 3. Reactivity- capacity of a substance to combine with another substance( iron + O = rust)

Chemical and Physical Properties Are not alike Can observe physical properties without changing the identity of the substance Can observe chemical properties only in situations in which the identity of the substance changes

Changes in Matter Physical Change-affects 1 or more physical properties of a substance without changing the identity of the substance Example- cutting hair, melting popsicle, crushing a can, sugar dissolving Do not change identity of substance During physical change-energy is absorbed or released, arrangement of atoms is the same even if looks different

Chemical Changes Chemical change- happens when one or more substances are changed into entirely new substances that have different properties. Examples- food digested, battery dies, oxygen breathed, fruit ripening

Chemical Changes Form new substances Interaction – the action or influence between things Can be detected- change in color, odor, fizzing, foaming, sound, heat, light Chemical changes can not be reversed by physical changes. (bread baking, rust, milk turning sour)

Breaking Down Mixtures Mixtures can be separated by physical changes. Mixtures are not chemically combined. Breakdown by removing pieces, heat, distillation, centrifuge, evaporation

Breaking Down Compounds Breakdown through chemical changes heat, electric current, chemical changes