Review WHMIS and MSDS 1.0

1.2 Properties and the Classification Of Matter

Propeties Used to Classify Substances
Physical Properties describe the physical appearance and composition of substance
Boiling point or condensation point
Melting Point or freezing point
Malleability; ability to be beaten or rolled into sheets ductility; ability to be stretched into a wire colour state solubility; ability to dissolve crystal formation; crystalline appearance conductivity;ability to conduct electricity pr heat magnesium Chemical Properties describe the reactivity of a substance. i.e. how a substance react with another substance ability to burn; combustion(flame, heat, light) flash point; temperature needed to ignite flame behaviour in air; tendency to degrade, react or tarnish reaction with water; tendency to corrode or dissolve reaction with acids; corrosion sometimes bubble formation reaction with heat; tendency to melt or decompose reaction to red and blue litmus; red—acid, blue—base no colour change neutral

Pure Substances and Mixtures
In a pure substance all the particles that make up the substance are identical, i.e. its chemical and physical properties remain constant. Identifiable by observing the physical properties
A pure substance is either an element or a compound
An element is a pure substance and is made up of only one type of atom
A compound is a chemical reaction of two or more elements in a specific ratio

A mixture is a combination of pure substances; the proportions in a mixture will vary
In a mechanical mixture the different substances are visible heterogeneous
In a suspension there is a cloudy mixture where particles can be separated
A colliod is a cloudy mixture in which particles of different substances are too small to be separated
A solution or homogenous mixture in which the particles of the different substances are not visible

Chemical Reactions
A chemical change is also called a chemical reaction. A chemical reaction occurs when a substance or substances combine to make a different substance or substances. **Energy is always absorbed or realized during a chemical reaction.

Recognizing Chemical Reactions
All reactions share certain characteristics. These include
All reactions involve the production of new substances with different properties
All reactions involve the flow of energy. Endothermic rxn’s absorb from the environment and exothermic rxn’s release into environment.
Many reactions cause a phase change such as the formation of a gas/bubbles and formation of precipitate that appears as cloudiness in a previous mixture
All rxn’s are consistent with the law of conservation of mass

A 1.3 Read Devloping Ideas About Matter pg 18-21

John Dalton
John Dalton was an english physicist and chemist who discovered atoms. He based his model on experiments he did in combining electrons
Daltons Model; Sphere Model (billiard ball model)
All matter is made up of small indivisible particles called atom; he imagined them like small spheres
All the atoms of an element are identical in properties such as size and mass
Atoms of different elements have different properties
Atoms of different element have different properties

J.J Thomson
An english Physicist who discovered the electron. Thomsons model was the raison bun
Thomson was experimenting with beams of particles produced in a vacuum tube. Thomson's experiment showed the beam was made up of negative charges. By testing many different elements, he showed that they all produced the same type of beams. This suggested that atoms of different elements contained smaller particles that were identical.
Thomson's model suggested that all atoms were made up of smaller subatomic particles, which were uniquely combined. He suggested that an atom was a sphere with a positive charge with negative particles embedded on.
Nagoaka proposed a different model where the electrons where place in a