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The flare includes .........................., which makes a red flame.
strontium nitrate
Word chemical equation Magnesium reacts with oxygen
magnesium + oxygen-> magnesium oxide
sodium peroxide symbol
Na2O2
True& false Magnesium is more reactive than Sodium
False
True& false Some metals react with oxygen to make oxides.
True
1) Which statement best describes an exothermic reaction?
A reaction that only happens in cold conditions
A reaction that releases heat to its surroundings
A reaction that absorbs heat from its surroundings
A reaction that does not involve energy
2) Which of the following is an example of an endothermic reaction?
Ice melting into water
A candle flame giving off heat
Burning wood
Explosion of fireworks
3) A grade 7 student wants to know if the reaction of hydrochloric acid and sodium hydroxide solution is exothermic or endothermic. He did an experiment for this reaction. Give the name of this reaction:
Neutralization
Burning
Combustion
Dissolving
4) After reacting hydrochloric acid with sodium hydroxide, the temperature has increased from 21˚C to 52˚C. This reaction is
isothermic
Exothermic
Athermic
Endothermic
5) Which process releases heat energy to the surroundings?
Freezing water
Cooking an egg
Boiling water
Melting wax
6) Which is the best scientific question for investigating fuels?
Which fuel looks nicer?
Why are fuels important?
Which fuel is the best?
Which fuel releases the most heat energy when burned?
7) In an investigation comparing fuels, what is the independent variable?
The size of the container
The type of fuel used
The temperature change of water
The amount of heat released
10) Why is it important to keep control variables the same?
To ensure a fair test
To make the experiment more fun
To increase the temperature
To change the results
9) Which of the following should be kept as a control variable?
Type of fuel
Amount of heat released
Volume of water in the container
Temperature change
