Physical/ Chemical changes Flashcards
What are evidences of a chemical reaction?
- Bubbles
- A colour change
- A large energy change: give out energy like combustion or take in energy to feel cold. (temperature)
What is a physical change?
A physical change is a reversible process that doesn’t involve bonds being broken and made. No new substances are formed.
What is a chemical change?
A chemical change is when bonds are broken and made to make new substances.
Give examples of a physical change.
Melting, boiling, dissolving
When are tables used?
To show data in order. eg. biggest to smallest. Also, used to record results.
When are scatter graphs used?
Find a link between variables.
Both variables are quantitive - could be discrete or continous.
Give an example of when a scatter graph could be used?
Scatter graph:
A graph showing how the weigth affects the height of someone.
When are line graphs used?
Show how a dependent variable affects a n independent variable.
Both variables are continous.
Joined with a line of best fit.
Give an example of when a line graph could be used?
Line graph:
A graph showing how the mass added will affect the extension of a spring.
When are bar graphs used?
Comapre sets of data
Independent variable is discrete.
Dependent variable is quantitive.
Give an example of when a bar graph could be used?
Bar garph:
show the density of different metals.
What is quantitive data?
Quantitive data can be counted and expressed using numbers.
What is qualitative data?
Describes quantites that are observable.
What is continous data?
- Measured
- Have any value
What is discrte data?
- Counted
- Whole numbers only
