vaporisation, Freezing, Condensation
The answer you are looking for is the second option, "<span>Matter can be divided into two groups: pure substances and mixtures."
A pure substance can describe a pure element or chemically bonded elements. A pure substance cannot be broken down into further substances. An example of these would be Fe (iron) or O2 (oxygen).
A mixture is a structure made from physically combining different non-bonded substances. An example of a mixture is blood.
Both pure substances and mixtures are types of matter.</span>
Answer:
D.) the density changed
Explanation:
This would be the answer because it is a specific amount of Nitrogen undergoing a physical change. Since the color and boiling point don't influence a change in volume, those are ruled out. Also, nitrogen's molecular mass never changes, so that would not make sense either. But if the density, which is mass/volume, has changed (more specifically decreases) then it means the volume has increased.
Hope this helps.
