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WorksheetsScience 7 - Material Changes
Total questions: 25
Worksheet time: 15mins
Q1. Which is an example of a chemical change?
burning of wood
heating glass and bending it
boil water
melting an ice
Q2. Iron + Sulfur --> Iron sulfide
From that word equation, what is/are the reactant(s)?
iron
sulfur
iron and sulfur
iron sulfide
Q3. When something burns, it reacts with the _________ in the air.
CO2
CO
O2
C
Q4. Why is it advisable to look at directly at the flame when burning magnesium ribbon?
It can burn our eyes.
It can melt our eyes.
Magnesium burns very brightly and the light could harm our eyes.
It can warm our eyes.
Q5. When magnesium reacts with hydrochloric acid, gas is given off. The gas is called ________.
Oxygen
Hydrogen
Carbon dioxide
Carbon monoxide
Q6. Zinc + Sulfuric acid ---> ....... + Hydrogen
What is other product formed in this chemical reaction?
zincate
zinc acid
zinc sulfate
sulfate
Q7. What are the products formed when Copper carbonate reacts with hydrochloric acid?
Copper chloride + water + carbon dioxide
Copper chloride
water
carbon dioxide
Q8. What happens in a chemical reaction?
Atoms form new combinations
Atoms do not form new combinations
Q9. In detecting chemical reactions, there are few clues we can look, except ...
A colour change
A gas is given off
Heat is produced
No new substances
Q10. What is formed when iron reacts with oxygen in the air?
iroxy
rust
crumble
substances
Q11. From this experiment, we can conclude that rusting need ______________.
oxygen
water
oil
oxygen and water
Q12. How can iron be protected from rusting?
by painting it
by drowning it
by covering it with another iron
all of the above
Q13. Whay type of change does melting of chocolate belong to?
chemical change
physical change
Q14. The compound formed when magnesium reacts with oxygen is _____________.
Magnesium oxide
Magnesiumide
Magnesium oxygen
Oxymagnesium
Q15. What is the chemical name for rust?
Fero
Iron(III) oxide
rusting
Iron man
Q16. Bending a metal rod is an example of a __________.
Physical Change
Chemical Change
Q17. A copper penny turning greenish after a few years. What type of change does it show?
Chemical Change
Physical Change
Q18. Which is the name of the solid substance formed in this figure?
aqueous
precipitate
acid
solution
Q19. Which evidence shows that a chemical reaction has occurred?
dissolving
melting
formation of a gas
bending
Q20. You know that a chemical reaction has occurred if
there is a precipitate (new solid)
there is a color change.
there is a temperature change.
All of these answers are evidence.
Q21. What indicates a chemical reaction occurred?
Heat or Light is released
heat or light is produced
gas (bubbles) produced
color change
all of the above
Q22. The starting materials in a chemical reaction are called ___________.
Products
Reactants
Starters
Q23. In chemical reactions, what does the Law of Conservation of Mass mean?
Atom is not created or destroyed.
The total mass of the reactants is greater than the total mass of the products.
The total mass of the reactants is less than the total mass of the products.
Matter is not changed.
Q24. The substances listed on the right side of a chemical equation are the
Solutes
Reactants
Products
Precipitates
Q25. When a candle melts, it is a ___________________ change.
chemical
physical
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