Chemistry Gr 9 & 10 Review
Module One: Grade Nine Topics
Physical Change: This is a usually reversible change in which the form of matter is altered, but is not chemically changed to another substance.
Melting an ice cube is an example of a physical change.
The ice cube changes states: from a solid to a liquid (water).
You can physically see this change.
No new substance is formed: the matter in the liquid is the same as it was in the ice cube.
It is reversible: you can freeze the liquid to turn it back to ice.
Therefore this is an example of a physical change!
Dissolving sugar into water is also an example of a physical change.
The sugar disappears into the water making a solution.
No chemical reaction occurs.
No new substance is formed: it is just sugar in water
It is also reversible: if you boil the water there will be traces of sugar left.
Therefore this is an example of a physical change.
Chemical Change: A usually irreversible chemical reaction that causes a change in matter’s chemical properties resulting in the formation of another substance.
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When a chemical change occurs after a chemical reaction there are clues for you to know that the change was chemical and not physical.
Pure Substance: This is a substance that is made up of only one type of molecule or atom. (Making it pure).
There are 2 types of pure substances: an element and a compound. Element: A substance that cannot be broken down by chemical means. An element is a pure substance because it is made up of one type of atom it also cannot be broken down further into another substance. (This deems it pure)
Compound: A substance that is made up of 2 or more elements, it is still considered a pure substance because while the elements bond so do the atoms. Therefore there is only one type of atom in the compound.
Impure substance- Mixture: A substance that is made up of 2 or more different particles (Making it impure).
There are 2 different types of mixture: Homogenous
Physical Change: This is a usually reversible change in which the form of matter is altered, but is not chemically changed to another substance.
Melting an ice cube is an example of a physical change.
The ice cube changes states: from a solid to a liquid (water).
You can physically see this change.
No new substance is formed: the matter in the liquid is the same as it was in the ice cube.
It is reversible: you can freeze the liquid to turn it back to ice.
Therefore this is an example of a physical change!
Dissolving sugar into water is also an example of a physical change.
The sugar disappears into the water making a solution.
No chemical reaction occurs.
No new substance is formed: it is just sugar in water
It is also reversible: if you boil the water there will be traces of sugar left.
Therefore this is an example of a physical change.
Chemical Change: A usually irreversible chemical reaction that causes a change in matter’s chemical properties resulting in the formation of another substance.
.
When a chemical change occurs after a chemical reaction there are clues for you to know that the change was chemical and not physical.
Pure Substance: This is a substance that is made up of only one type of molecule or atom. (Making it pure).
There are 2 types of pure substances: an element and a compound. Element: A substance that cannot be broken down by chemical means. An element is a pure substance because it is made up of one type of atom it also cannot be broken down further into another substance. (This deems it pure)
Compound: A substance that is made up of 2 or more elements, it is still considered a pure substance because while the elements bond so do the atoms. Therefore there is only one type of atom in the compound.
Impure substance- Mixture: A substance that is made up of 2 or more different particles (Making it impure).
There are 2 different types of mixture: Homogenous