Physical Properties: characteristics of matter that can be observed without changing it to another substance.

Physical Properties of a substance can be identified using your senses or by measurement.

Examples: color mass texture volume taste density smell boiling point freezing point

Chemical Properties describe how a substance changes into another substance.

Examples: flammability (ability to burn) electrolysis (electricity breaking bonds) oxidation (the ability to react with oxygen, which causes apple slices to turn brown and iron to rust), toxicity (the ability to be poisonous),

How do you know if new substances have formed ? If new substances have formed ………

….you will see signs of a chemical reaction: the production or absorption of heat or light energy, smoke, bubbles of gas, a smell, a sound, a change in color

Flammability is a chemical property: it causes chemicals to change into new chemicals

Flammability would be a chemical property of Paper and wood, but not one of water. Often smoke is produced

Electrolysis: can change substances into new substances and is a chemical property

Water is placed in the middle tube, it separates in two tubes The battery is connected to each tube As the electrical current enters each tube the water (H20)is broken down into hydrogen (H) and oxygen (O)

Oxidation is a chemical property. Steel and iron reacts with water and changes into new substancesSome kinds of substances don’t Have this property such as wood, plastics, and other nonmetals

Fe + H20 --- FeO + H2 Iron water Rust hydrogen

The steel changes color

Physical and Chemical Change

In a physical change, the substances are not altered chemically. No new products are formed. Chemical bonds are not broken in a physical change. A physical change can affect size, shape color phase (i.e. gas, liquid, solid) separated or combined.

Examples:

when ice melts

breaking a glass

dissolving sugar in water

Chemical Changes

Occur when