Page 16 - Science Course 3 (Book 2)
P. 16
Mo8-L1: Key Concept Check
Direction: Complete each item below on the lines provided
1. The principle that mass is never lost in physical and chemical changes is known as the law of
2. The ashes left by a forest f re don’t weigh as much as the trees did. Knowing that mass is never destroyed,
explain what happened to some of the mass of the trees as they burned.
3. When water freezes, it expands in volume by 10 percent. If you froze 200 g of water, what would be the
mass of the resulting block of ice? Explain your answer.
4. What happens to the mass of a soft drink when you open it?
5. If you could put a sealed room on a very sensitive scale and open a thousand soft drink cans inside it,
would the mass reading on the scale go up, go down, or stay the same? Explain your answer.
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