3. A student mixes a solid powder into a beaker of fluid. Which of the following would indicate that a chemical change has definitely occurred?

Explanation:

A chemical change is a change in which a new kind of substance is produced. Such changes are always accompanied by energy changes.

They are mostly reversible.

Some examples of such reactions are combustion, rusting of iron, precipitation, rancidity of butter, souring of milk.

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.

let that person have a turn to speak : )