Question

a precipitate is a (select two)
an aqueous solution
a sign of a physical change
solid forming from two aqueous solutions
a sign of a chemical change

Explanation:

1. Analyze each option:

• "an aqueous solution": A precipitate is a solid, not an aqueous solution, so this is incorrect.
• "a sign of a physical change": Precipitation involves a chemical reaction (formation of an insoluble solid from solutions), so it's a chemical change, not physical. Incorrect.
• "solid forming from two aqueous solutions": Precipitation occurs when two aqueous solutions react to form an insoluble solid (precipitate). Correct.
• "a sign of a chemical change": Since a new substance (the precipitate, a solid) is formed from the reaction of two solutions, it indicates a chemical change. Correct.

Answer:

C. solid forming from two aqueous solutions, D. a sign of a chemical change