Vocabulary
A reaction requiring the absorption of heat.
Endothermic chemical reaction
The variable that is being measured.
Dependent variable
glass breaking, cutting paper, painting a wall, changes in state of matter
What happens to the temperature in an endothermic chemical reaction?
Increases
Anything that has mass (weight) and takes up space.
Matter
The variable that changes.
Independent variable
Two examples of chemical change
cooking, baking, iron rusting, fireworks, reacting with air or acid
What happens to the temperature in an exoothermic chemical reaction?
Decreases
Type of change where a new substance is created.
Chemical change
ou want to figure out which brand of microwave popcorn pops the most kernels so you can get the most value for your money. You test different brands of popcorn to see which bag pops the most popcorn kernels.
What is the dependent variable?
Number of popcorn kernels popped
A chemical change can produce.....
baking, cooking, photosynthesis, melting and evaporation.
A type of change where the substance stays the same, but size and shape may change.
Physical change.
You want to see which type of fertilizer helps plants grow fastest, so you add a different brand of fertilizer to each plant and see how tall they grow.
What is the independent variable?
Different brands of fertilizers
What kind of change do you observe when sugar dissolves in water? explain
physical change
When sugar dissolves in water to form a sugar solution (sugar in water), its chemical composition does not change. Hence it's a physical change.
Two examples of exothermic reactions.
freezing, condensation, burning wood, lighting a candle, rusting, fireworks..etc
This type of matter keeps a definite shape.
Solids.
You're interested in how rising sea temperatures impact plant life, so you design an experiment that measures the number of plants in a sample of water taken from a specific ocean site under varying temperatures.
Give 2 control variables
Same plant
Same amount of water
What physical change could be considered a chemical change as well?
Color
Painting a wall - physical change
Iron rusting- chemical change
Two similarities between endothermic and exothermic chemical reactions.