Question

1. which of the following physical characteristics is the same for a particular substance, regardless of the sample size?

a. mass
b. volume
c. heat content
d. melting point

1. fresh milk has several parts that a farmer can separate and sell. a farmer removes the top - layer of fat from fresh milk. what property does the farmer use to separate the fat from the rest of the milk?

a. density
b. magnetism
c. boiling point
d. electrical conductivity

1. theresa has a pile of sand grains and salt grains mixed together. she wants to separate the sand from the salt. what method can she use to separate these two substances?

a. heat the pile to 100°c so that part of the pile boils.
b. place a magnet over the pile to pull out the magnetic parts.
c. sift the pile through a screen with holes that are one - centimeter wide.
d. stir the pile into a bowl of water, and then pour the water out of the bowl.

Explanation:

• For question 7: Melting point is an intensive property and remains the same regardless of sample size. Mass, volume and heat content are extensive properties and depend on the amount of substance.
• For question 8: Fat in milk has a different density than the rest of the milk, allowing separation by density - based methods like skimming.
• For question 9: Salt dissolves in water while sand does not. Stirring the mixture in water and pouring out the water (decanting) will separate the salt from the sand.

Answer:

1. d. Melting point
2. a. Density
3. d. Stir the pile into a bowl of water, and then pour the water out of the bowl.