Chemical Change
Physical Change
Chemical Properties
History of the atom
Physical and Chemical Change
100
Give 4 examples of chemical change.
Example answers: iron rusting, necklaces tarnishing, baking cookies, baking pancakes, wood rots, etc.
100
Which is a physical change?
a) Burning Magnesium
b) Dissolving salt in water
c) Mixing vinegar and baking soda
d) Cutting up strawberries
b) Dissolving salt in water
100
The ability of matter to combine chemically with other substances.
REACTIVITY
100
What do we call particles that make up all matter in the universe.
Atoms
100
A _____________________ lists all the elements in the universe in an organised structure based on atomic numbers.
Periodic table
200
How many substances join to form new chemical properties?
Two or more.
200
What are the three states of matter.
Solid, liquid and gas
200
The ability of a chemical to burn or ignite or cause fire.
FLAMMABILITY
200
JJ Thomson discovered that atoms contained tiny negative particles. What were these particles callled?
Electrons
200
Give 1 example of physical change and chemical change.
...
300
Every time a substance burns and there is fire, it is because it is reacting with what element in the atmosphere?
Oxygen
300
When a candle is burning, there is both a physical and chemical change happening. Explain which part is the physical change.
The wax melting is a physical change as it will return to solid after it cools down.
300
The capacity of substances to be mineralized by free‐living bacteria.
BIODEGRADABILITY
300
Ernest Rutherford explained that the centre of the atom was made up of a very heavy and small _________________ that was made up of protons and neutrons
Nucleus
300
Toasting bread is a chemical change. List the observations that confirms this as a chemical change.
- Colour change
- A smell is produced
- The reaction is not reversible
400
What are the reactants in the following equation?
Hydrochloric acid + Magnesium --> Hydrogen + Magnesium Chloride
Hydrochloric acid and magnesium
400
Why is freezing water a physical change when you start with water and end with ice?
No new substances are formed. Ice is still water but in solid form.
400
Oxygen has a formula of O2. Is it a compound or a molecule. Explain.
It has two atoms chemically combined together.
400
Which scientist developed this model of the atom? Full name
Niels Bohr
400
Explain what is meant by exothermic reaction.
A reaction that releases heat energy. Mixing something that gets hotter.
500
Photosynthesis is a chemical reaction occurring in plants to make food. List all the chemicals involved in this process.
Carbon dioxide
Oxygen
Water
Glucose/sugar
500
Give 4 examples of a physical change.
Melting, boiling, evaporation, condensation, freezing, sublimation, deposition.
500
Give 3 examples of chemical properties.
Oxidation, reactivity, flammability, biodegradability
500
Niels Bohr explained that electrons exist in energy levels. What year did he introduce this idea?
1913
500
Physical or Chemical Change: Your friend decides to toast a piece of bread, but leaves it in the toaster too long. The bread is black and the kitchen is full of smoke.
CHEMICAL CHANGE