2points
the ph indicator bromothymol blue turns yellow when co2 gas is added to a
solution and blue when co2 is removed from a solution. an experiment will
test how the intensity of light affects the rate of photosynthesis in algae.
which of these should be a control for this experiment?
o
a. algae that are placed in a blue solution and kept in direct sunlight
o
b. algae that are placed in a yellow solution and kept in the mark
o
c. algae that are placed in a yellow solution and kept in direct
sunlight
o
d. algae that are placed in a blue solution and kept in the dark
submit

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