Unit A: Section 1.0 Flashcards
What does WHMIS stand for?
Workplace Hazardous Materials Information System
What is MSDS?
Identifies physical and chemical hazards associated with a product
What do Physical Properties describe?
They describe the physical appearance and composition of a substance
What are the common Physical properties
- Boiling point
- Melting point
- Freezing point
- Malleability
- Ductility
- Colour
- State
- Solubility
- Crystal formation
- Conductivity
- magentism
What do Chemical properties describe?
The reactivity of a substance
What are the common chemical properties?
- Ability to burn
- Flash point
- Behaviour in air
- Reaction in water
- Reaction with acids
- Reaction with heat
- Reaction to litmus paer
What is a flash point?
Temperature needed to ignite a flame
What happens if a substance undergoes a physical change?
It still has all the same properties and is reversible
What happens if a substance undergoes a chemical change?
A new substance is formed and it is irreversible
What are the 2 classifications of matter?
Pure substance or Mixture
What is a pure substance?
All the particles that make up the substance are chemically combined and identical
What are the 2 components of a pure substance?
Element and Compound
What is an element?
A pure substance that cannot be broken down into other substances and made of only one type of atom
What is a compound?
An group of elements that are chemically combined and in fixed proportions
What is a mixture?
A combination of pure substances that are not chemically combined and proportions can vary
What is a mechanical mixture/heterogeneous mixture?
When the different components are visible such as soil
What is a suspension?
A type of mechanical mixture where the components are in different states such as mud
What is a colloid?
The same thing as a suspension but the particles cannot be easily separated
What is a Solution or Homogeneous mixture?
One substance dissolved within another but it looks the same throughout
What is a chemical reaction?
A process that occurs when substances react to create different substance
What are some ways to preserve food?
Heating Freezing Salting Fermentation Smoking
What is Sterilization?
Any process that kills micro-organisms
How does freezing sterilize food?
The o-organisms that low temperature prevents the growth of micro-organisms that cause decay
How does salting sterilize food?
The salt draws the water out of the meat and the bacteria which kills them or inactivates them
How does fermentation work?
The lactobacilli creates lactic acid which is a preservative. It prevents the growth of bacteria that causes food to rot
What lactobacilli?
A bacterial found in food that that convert starches and sugars into lactic acid
What are the positives to lactobacilli?
- Preserves food
- Increase vitamin levels
- Makes food digestible
How does smoking preserve food?
Introduces antioxidants and formaldehyde to slow the rotting process
What are the 3 ages of metal?
- Copper
- Bronze
- Iron
Why was copper a good metal?
It was harder, so it could be used to make tools and weapons, and jewelry.
What is Native Copper?
Copper found in the arctic ocean that is found in pure form.
What did the early Inuit use copper for?
- Handles
- Pots
- Staples
- Rivets
What was the problem with copper?
When they hammered it into shapes it began too brittle and broke easily.
How did they solve the copper problem?
By melting it to strengthen it
What is annealing?
The heating of a metal before shaping it
What is smelting?
Separating metal by melting it
What was a positive to smelting?
Before when things were hard to find in pure substances now it was able to be found in mixtures and separated
What did Aristotle believe about matter?
It was made from earth, fire, water, and air
Who came up with the idea of atoms?
Democritus
What is alchemy?
A combination of science and magic
What did Robert Boyle discover?
By experimenting with volume and gas he concluded that gasses are made up of tiny particles
What did Antoine Lavoisier Discover?
The law of Conservation of mass
How did Antoine Lavoisier discover the Law of Conservation of Mass?
He measured masses of substances that reacted together and the substances created. He discovered that mass is neither produced nor lost in a chemical reaction
What did John Dalton discover?
The billiard ball model of Atoms. He imagined they were small spheres that could have different properties and varied in size color and mass
Describe John Daltons Atom?
The Billiard Ball
- All matter is made of small indivisible particles
- All atoms of an element are identical in properties such as size and mass
- Atoms of different elements have different properties
- Atoms of different elements could combine in specific fixed ratios
What did J.J. Thomson add onto John Daltons Atom?
He added electrons
What did J.J. Thomson discover?
The electron
How did J.J. Thomson discover the electron?
He was experimenting with beams of particles produced in a vacuum. And they were all turned out to be negative which means they all had something in common. Electrons
Who created the raisin bun model?
J.J. Thomson
Describe J.J. Thomsons model of the atom
The raisin bun model was a positive sphere with electrons embedded within it
What did Ernest Rutherford change about J.J. Thomson’s atom model?
He said that the core of the atom was called a nucleus and it was positively charged and negative electrons we floating are the nucleus but not in a specific direction
Who was the first scientist to use nucleus?
Ernest Rutherford
What experiment did Rutherford use to determine his atom?
He released a radioactive material that fired positively at gold and he assumed the they would pass right through but instead, they were deflected which meant they had a strong positive charge
Describe Ernest Rutherfords atom?
It had a dense positively charged nucleus and around it was mostly empty space with electrons floating around
What did Neils Bohr discover about rutherfords atom?
He said that electrons surround the nucleus at different energy levels, therefore, they travel in orbits.
What experiment did Neils Bohr do to conclude that electrons travel in orbits?
He discovered that different lights are emitted when electrons from different energy falls
Who was the scientist that discovered how electrons flow in orbits?
Neils Bohr
What was Neils Bohr’s description of atoms?
They had a positively charged nucleus and electrions orbited in specific energy levels
Describe the Quantam Mechanics Atom
Electrons are thought of as a cloud of negative charges and occupy the whole space at the same time at different electricity levels
What was bronze made out of?
Copper and tin
How did they make bronze?
They smelted copper and tin together and the metal produced was much stronger
How did the Iron age begin?
They realized that Iron could be found in mineral compounds so they were able to smelt it out. Just like Copper
