Grade 9 Science Unit B Topic 1-2 Flashcards
WHMIS
Workplace Hazardous Materials Information System
2 categories of Hazards
Physical Hazard
Health Hazard
Physical Hazard
Identified by:
Sate (solid, liquid, gas)
Physical Properties: (explosive, corrosive, flammable)
19 categories of Physical Hazard (Ex. Flammable Gases.)
Health Hazard
Identified considering:
Potential exposure routes (inhalation, ingestion)
Nature of harm (Effect immediate or not)
12 categories of health hazards (e.g… Carcinogenicity)
Suppliers
Responsible for classifying hazardous products
Importers
Make sure it’s correctly classified and labelled to meet WHMIS requirement
Employers
Imports products for the workplace, the employer has duties of suppliers
Workplace labels
Must have:
product identifier
safe handling instructions
Supplier labels
Must have:
Product identifier
hazard pictograms
signal words like danger or warning
Hazard statements
Precautionary statements including first aid info
Supplier identifier
Must be placed on container before import or sale
Safety Data Sheet ( SDS)
Documents that summarize info about a product and any precautions
More information on the label
Usually provided by the supplier
Binder with SDS for all the chemicals we have
Consumer Chemical Hazard
Hazardous chemicals intended for household, personal or retail use
Sublimation
Occurs when a solid changes directly into a gas (Solid to Gas)
Deposition
Occurs when a gas can change directly into a solid (Gas to Solid)
Plasma
Fourth state of matter
Results when a large amount of energy is added to Gas
Examples: Neon signs, Stars like our sun, lightning.
Properties
Characteristics that can be used to describe a substance
2 Types of properties
Physical properties
Chemical properties
Physical Properties
Describe the physical composition of the substance:
Example:
Melting point (Solid to Liquid)
Boiling point (Liquid to Gas)
Hadeness- the ability to resist being scratched
Crystal shape
Malleability- Being able to shape an object without it breaking
Solubility- Ability of a substance to be dissolved in another
Ductility- capable of being drawn out into wire or thread
Density- the amount of mass in a given volume of substance
Conductivity- how well can an object transmit and conduct electricity
Chemical Properties
Describe how a substance interacts with another substance
Example:
Reaction with Acids
Ability to burn
Reaction to water
Behaviour in air
Reaction to heat
Pure substance
Made of only one kind of matter and has unique properties that set it apart from other kinds of matter
Element
Sub-Category of a pure substance
A material that cannot be broken down into any simple substance. (Ex. Calcium, Hydrogen, Bromine)
Compound
Sub-Category of a pure substance
A compound is formed when 2 or more elements combine chemically in fixed ratios. (Ex. H20-water)
Mixtures
A combination of pure substances. (May be different from compounds as they do not combine chemically)
Remain in their original form
Mechanical Mixtures
Different substances that make up mixtures are visible
Also known as a Heterogeneous mixture
Ex, Soil, Sand, Mixed veggies
Solution
Looks like 1 substances.
Also known as a Homogenous mixture
Aqueous solution dissolved in water
Suspension
A cloudy mixture in which tiny particles of one substance are held within another.
If you let it sit it will usually separate out into separate parts
Ex. Muddy water, paint, dust in the air, flour in water
Colloid
Cloudy mixture
The particles are so small that they cannot be filtered out easily.
Example: Corn starch and water, Homogenized milk
Physical Change
Occurs when a substance’s appearance or state changes, but its composition stays the same
Example: Ice melts into water. The state has changed, and appearance is different. However. ice is made of H2O ,and water is H2O ,so the actual substance is the same
Physical changes are almost always reversible
Chemical Change
Occurs when 2 or more materials react and create new materials
New materials have completely different properties from the original substances
Chemical Chsnge always results in the formation of a different substance or substances
Example. Frying an egg
When you fry an egg it forms a new substance.
It is irreversible
Evidence of Chemical Change
Change in colour (e.g. Add bleach in denim- colour changes)
Change in odour (e.g. Lightning a match- distinctive odour)
Formation of solid or gas (e.g. When vinegar is added to baking soda, carbon dioxide is formed)
Release or absorption of heat energy ( When gasoline is burned heat is released)
Alloy
Mixture of metals
Democritus
About 400 BC
Greek Philosopher
Used word “atomos” to describe smallest particles that could not be broken down any further
“Atomos” means “indivisible”
He stated that all things were made up of different “atomos” and that by mixing the “atomos”, you could create new materials
Democritus Vs. Aristotle
Aristotle believed all things were made up of air, fire, earth, and water
Aristotle was well-known and respected, and his opinion was favoured
Alchemy
Also known as pseudo-science:
Not real because it’s not based on facts
Searched for a way to turn any matter into gold because they didn’t understand the nature of matter.
Al-Razi
An alchemist
Discovered change of state to create a plaster of Paris
A combination of substances becomes a quick, hardening paste when mixed with water
Andreas Libau
German alchemist
Published “Alchemia” which highlighted the achievements
Also made note of how to prepare chemicals such as hydrochloric acid, making his book the first chemistry text published in 1957
Robert Boyle
1660 - An Irish Aristocrat
Interested in properties of gases and their behaviour under pressure
Echoed Democritus opinion
That particles would bond together to form different substances
Antoine Laurent Lavoisier (and his wife Marie)
1770’s French scientist
Developed a sytem for naming chemicals
Based on their interactions
Known as “The father of modern chemistry”
His wife continued his work after he was executed in the French Revolution.
John Dalton, 1808
Suggested that matter was made up of elements which were pure substances that contained no other substances
First to come up with the structure of an atom which was a particle that made up an element
Identified each atom had its own mass, and no two masses were the same
Created ‘Billiard ball model”
J.J. Thomson
1897- British Physicist
The first to discover sub-atomic particles, discovered the electron
The negatively charged electrons balanced the positive atoms, so the atoms had no change.
Hantaro Nagoka
1904- Japanese Physicist
He refined the model of the atom to resemble a mini solar system, with electrons orbiting around the atom
Ernest Rutherford
1911- British scientist
Won Nobel Prize for work he did at McGill University in Montreal
Using Thomson’s model, he conducted experiments that supported the existence of a tiny, positive-charged centre
He calculated the size of the nucleus was 1/1000th the size of the atom
Niels Bohr
1931- Danish researcher
Worked with Rutherford
Further model of the atom by noting that electrons ( negative charge) move in specific orbits or “electron shells” and jump these orbits to lose energy
James Chadwick
1932- British Physicist
Discover a nucleus filled with positively charged particles called protons and neutral particles called neutrons.
Neutrons have the same mass as a proton, but no charge
Jons Jacob Berzelius
Suggested using letters instead of pictures
Would capitalize the first letter of the name of the element, and add a lowercase second letter if the first had already been used.
