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Year 8 Chemistry Homework
Due: Monday 6th October
Name:_____________________
Question 1: Physical & Chemical Changes
state burn
reversible
physical
melt
different particles colour
irreversible
chemical
If you heat ice it will ____ into water. This is a _________
change. Physical changes often involve a change of _____. They
are __________ which means they can be easily undone. In a
physical change, no new material is formed.
If you heat bread it will _____ and become toast. Burning is a
________ change. Chemical changes are ______________
meaning they are difficult to undo. We can sometimes
recognise chemical changes because we see a ______ change.
In a chemical change, new materials formed that are
_________ to the starting materials. This is because the
_________ become rearranged.
a. Give an example of a chemical change.
b. Give an example of a physical change.
c. When a chemical change happens we sometimes see a
colour change. What other observations tell you that a
chemical change is happening?
_______________________________________________
Question 2: Metals and Acids
Fill in the blanks
Q.3 Explain the difference between and exothermic and
endothermic reaction
Hints:
 Which one gives off heat and which one takes it in?
 Why is heat given off or taken in (bonds)
 Give an example of each (ice melting and combustion)
_______________________________________________
_______________________________________________
_______________________________________________
Q.4 How can you use limewater to test for the presence of
carbon dioxide?
_______________________________________________
_______________________________________________
_______________________________________________