Justin is planning his science fair project. He wants to measure how oxygen levels affect the rate of photosynthesis in plants. Is this an example of a scientific investigation or an experiment? An experiment because it tests a cause and effect relationship An experiment because it does not ask a testable question An investigation because it uses only observations An investigation because there is a control group

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance