Worksheets6.6 E : Evidence of Chemical Change (10 Questions)
Total questions: 10
Worksheet time: 5mins
Name
Class
Date
1.
1. Which of the following is the BEST sign that a new substance might have formed?
a)
Baking soda and vinegar mixed together produce bubbles.
b)
Sugar dissolving in tea.
c)
Wood being cut into smaller pieces.
d)
Ice melting into water.
2.
2. Amaya mixed two clear liquids in a beaker. Suddenly, the beaker felt warm to the touch. What does this temperature change suggest?
a)
A physical change is definitely happening.
b)
A new liquid substance is being formed.
c)
A possible chemical change is taking place.
d)
The liquids are just mixing together.
3.
3. When you mix salt and water, the salt disappears. Is this evidence of a new substance forming?
a)
Yes, because the water now tastes salty.
b)
No, because the salt is still there, just dissolved.
c)
Maybe, it depends on how much salt is added.
d)
Yes, because the salt is no longer visible.
4.
4. Alex mixed two clear solutions. He observed a white solid forming at the bottom of the container. What is this solid called, and what does its formation suggest?
a)
It is called a precipitate, and it suggests a possible chemical change.
b)
It is called a residue, and it indicates a change in state.
c)
It is called a solution, and it means nothing new was formed.
d)
It is called a mixture, and it shows a physical change.
5.
5. Sarah noticed that when she left her bike outside in the rain, some parts started to turn a reddish-brown color. What does this color change likely indicate?
a)
The bike is just wet.
b)
The paint on the bike is fading.
c)
A new substance, rust, is forming due to a chemical change.
d)
The metal is getting colder.
6.
6. Which observation would BEST indicate that a gas has been produced during a reaction?
a)
The solid disappears.
b)
The liquid becomes cloudy.
c)
The container feels colder.
d)
Bubbles are forming in the mixture.
7.
7. Heating sugar in a pan causes it to turn brown and eventually black. What evidence suggests this is a chemical change?
a)
The change in color and the new smell.
b)
The pan gets hot.
c)
The sugar changes its state from solid to liquid.
d)
The sugar melts first.
8.
8. When magnesium metal burns in air, it produces a bright light and a white powder. What two pieces of evidence suggest a chemical change has occurred?
a)
The metal disappeared and light was produced.
b)
Light was produced and a new solid (the white powder) formed.
c)
The metal got hot and turned into a powder.
d)
The air around the metal heated up and the metal changed shape.
9.
9. Mixing flour and water creates a dough. Is this an example of a chemical change? Why or why not?
a)
Yes, because the flour and water are combined.
b)
No, because a gas was produced.
c)
No, because no gas, precipitate, or significant energy change is observed.
d)
Yes, because the dough has a different texture than flour or water alone.
10.
10. Imagine you mix two solutions together, and the resulting mixture becomes much cooler than the original solutions. What does this cooling suggest about the reaction?
a)
A precipitate is forming.
b)
A gas is being produced.
c)
Only a physical change is taking place.
d)
A possible chemical change is absorbing a temperature change.
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