Physical or Chemical Properties

What is chemistry? The study of matter and the way it interacts with other matter.

What is matter? Anything that has a mass and takes up space (volume). What is the smallest piece of matter?

Classifying matter Matter is classified into either mixtures or pure substances. Mixtures can be either heterogeneous or homogeneous. Pure substances can be either compounds or elements

Heterogeneous Mixtures Have two or more visible parts Example: Sand in water

Homogeneous Mixtures (solutions) Mixtures that have only one visible part. Example: Salt Water.

Compounds Pure substances whose particles contain two or more different kinds of atoms. Example: NaCl, H2O

Elements Pure substances that are made of only one kind of atom. Example: Hg, Ca, Na

A characteristic of the substance that is used to identify the substance. Colour, Hardness, Solubility, Lustre, Odour, Density, Melting/Boiling Point. Includes State: solid, liquid, or gas. Example: States of Water Physical Property

Chemical Property A characteristic or behaviour that becomes evident during or after a chemical reaction. Such as: Reactivity with water, Reactivity with acid, combustibility, Reactivity with air. Ex. Baking Soda

Alters only the form or state of a substance Alters only the form or state of a substance. NO new substance is created. The chemical composition remains the same. Usually reversible Examples: Change of state: Dissolving: Change of form: Physical Changes

Chemical Change Changes a substance into a new substance that has different physical and chemical properties, and a new chemical formula. Are NOT usually reversible. Substance cannot be easily changed into what it was before. Chemical changes are the result of chemical reactions.

Signs of a chemical change A permanent change in color. Bubbles of gas are produced. Two solutions mix to form a solid called a precipitate. Energy in the form of heat or light is released or absorbed. Electricity is produced.