Question

1. a group of students must identify four unknown solids based on their physical properties. they test mass, volume, solubility, and magnetism. their results are shown below: substance mass solubility in water magnetism a 50 g dissolves fully not magnetic b 75 g does not dissolve magnetic c 25 g dissolves partially not magnetic d 60 g does not dissolve not magnetic which conclusion is correct? a. substance b must be iron because it is magnetic. b. substance a must be salt because it dissolves completely. c. substance c must be wood because it dissolves partially. d. substance d must be sugar because it does not dissolve. 6. a group of students is asked to identify four unknown substances. they test them in different ways and record results in the table: substance test result a dissolves quickly in water b melts at 0°c c attracts to a magnet d floats in water which correctly matches the property being tested for substance d? a. mass b. density c. solubility d. conductivity

Explanation:

Step1: Analyze question 5

We need to evaluate each option based on the properties given. Just having a single property like magnetism, solubility doesn't uniquely identify a substance.

Option A

Substance B is magnetic. While iron is magnetic, there are other magnetic substances, so we can't be sure it's iron just from this property.

Option B

Substance A dissolves completely. But many substances dissolve completely in water other than salt, so we can't conclude it's salt.

Option C

Substance C dissolves partially. Wood doesn't dissolve in water, so this is incorrect.

Option D

Sugar dissolves in water, so this is incorrect.

Step2: Analyze question 6

The property of floating in water is related to density. If a substance floats in water, its density is less than that of water.

Answer:

1. None of the above
2. B. Density