Page 276 - Science Course 3 (Book 1)
P. 276
2. Explain why a synthesis reaction is considered to be the opposite of a decomposition reaction.
3. Describe combustion and give one example of a combustion reaction.
Mo7-L5: Key Concept Check
Direction: On each line, write the term from the word bank that correctly completes each sentence. Some
terms will be used more than once.
combustion decomposition double-replacement
single-replacement synthesis
1. In a reaction, the negative ions in two compounds switch places, forming
two new compounds.
2. In a reaction, one compound breaks down and forms two or more sub-
stances.
3. In a reaction, a substance combines with oxygen and releases energy.
4. In a reaction, one element replaces another element in a compound.
5. In a reaction, two or more elements or compounds combine and form
one compound.
6. Energy can be released as light or thermal energy in a reaction.
7. A reaction always contains O2 as a reactant.
8. The breaking down of hydrogen peroxide to form water and oxygen gas is an example of a
reaction.
9. The combining of Mg and O to produce MgO is an example of a reaction.
10. Burning fossil fuels to heat homes is an example of a reaction.
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