Which statement describes an extensive property of matter?
it changes with the color of a substance.
it changes when a new substance is formed.
it changes with the amount of sample that is present.
it changes with the composition of a substance,

Answer:

"It changes with the amount of sample that is present "  describes an extensive property of matter

Explanation:

In case of extensive property it rely upon the amount of matter present in the sample which further means mass and volume of the object. Other extensive property are, energy, enthalpy, entrophy, gibbs energy, heat, and also the internal energy. Mostly the extensive are the physical property of the object. They can vary depending upon the amount of the matter present. But when it comes to the intensive one they are the chemical property i.e. melting point, taste and colour etc.  

C

Explanation:

what is the general relationship between a galaxy's distance from earth and its speed?

the answer is:

the farther away a galaxy is from us, the faster it is moving away from us.