Science - Grade 4 - Review pt1

Tyrell makes salad dressing. He puts 150 mL of oil and 150 mL of vinegar in a jar and shakes it. After 5 minutes, the oil is on top of the vinegar. What can Tyrell conclude about the salad dressing?

• Oil is a solvent and vinegar is a solute.
• More oil is needed to dissolve the vinegar.
• The oil and vinegar have formed a mixture.

Physical changes happen when a substance changes, but its composition doesn't. Which of the following is a physical change?

• burning
• freezing
• decaying

Which of the following is the ability to cause change in matter?

• Energy
• freezing
• decaying

.. Of a compost pile is a clue that waste is rotting to form new substances. What is it?

• Smell
• Change of shape
• Change of size

An increase in temperature often speeds up a chemical reaction.

• Increase in temperature
• Decrease in temperature
• Temperature has no effect

The inner and outer planets can be grouped according to their characteristics.

• True
• False

Which of these does not apply to the outer planets?

• Densest planets
• Very cold temperatures
• Gases surrounding a solid core