Question

1. A fire is heating up a pot, which is cooking food. Which part of this reaction is the chemical reaction system?

all parts combined
the food
the pot
the fire

2.Which statement correctly describes how energy transforms?
When a fire is burning, visible energy is turned into chemical energy in the form of light and thermal energy in the form of heat.
When a fire is burning, chemical energy is turned into visible energy in the form of light and thermal energy in the form of heat.
When a fire is burning, thermal energy is turned into visible energy in the form of light and chemical energy in the form of heat.
When a fire is burning, visible energy is turned into thermal energy in the form of light and chemical energy in the form of heat.

3.Is a burning fire endothermic or exothermic? How do you know?
A burning fire is endothermic because a lot of heat is given off as the wood is converted into carbon dioxide and water.
A burning fire is exothermic because a lot of heat is given off as the wood is converted into carbon dioxide and water.
A burning fire is exothermic because a lot of heat needs to be applied in the form of fire to break the bonds of the wood.
A burning fire is endothermic because a lot of heat needs to be applied in the form of fire to break the bonds of the wood.

4.Use the energy chain to answer the question.
fire heats up a pot → pot cooks food → food fuels body → body releases heat during activity
Where is energy created in this energy chain?
Starting a fire is the creation of energy.
The food cooking is the creation of energy.
Energy is never created but simply recycled and changed into other forms.
The body processing food is the creation of energy.

5.A fire is heating up a pot, which is cooking food. Which part of this reaction is the chemical reaction system?
all parts combined
the food
the pot
the fire

Answer 1

1.Freezing is exothermic because as water bonds into ice, the energy from bond formation is released and heats up the surrounding environment.

2.When a fire is burning, chemical energy is turned into visible energy in the form of light and thermal energy in the form of heat.

3.A burning fire is exothermic because a lot of heat is given off as the wood is converted into carbon dioxide and water.

4.Energy is never created but simply recycled and changed into other forms.

5.The gasoline and spark

Answer 2

2. When a fire is burning, chemical energy is turned into visible energy in the form of light and thermal energy in the form of heat.

3. A burning fire is exothermic because a lot of heat is given off as the wood is converted into carbon dioxide and water.

4. Energy is never created but simple recycled and changed into other forms.