I don’t know let me go call and ask NASA real quick hold up
The answer is physical property.
Physical properties are the properties that does not require the substance changing into another substance, which is, chemical change. Physical properties are usually observable and measurable, such as melting points, density, odor, color etc. These does not require a chemical reaction to happen.
The opposite of physical property is chemical property, which is how the substance changes to another. Such as how sodium reacts with water to make sodium hydroxide and hydrogen.
Answer:
A particular atom will have the same number of protons and electrons and most atoms have at least as many neutrons as protons. An element is a substance that is made entirely from one type of atom. For example, the element hydrogen is made from atoms containing just one proton and one electron.
Explanation:
Answer: The molar mass of the unknown compound is 200 g/mol
Explanation:
Depression in freezing point is given by:

= Depression in freezing point
i= vant hoff factor = 1 (for molecular compound)
= freezing point constant = 
m= molality

Weight of solvent (benzene)= 0.250 kg
Molar mass of solute = M g/mol
Mass of solute = 26.7 g


Thus the molar mass of the unknown compound is 200 g/mol
For the first question, salt is soluble while sand is insoluble or not dissolvable in water. The salt should have vanished or melted, but the sand stayed noticeable or visible, making a dark brown solution probably with some sand particles caught on the walls of the container when the boiling water was put in to the mixture of salt and sand. The solubility of a chemical can be disturbed by temperature, and in the case of salt in water, the hot temperature of the boiling water enhanced the salt's capability to melt in it.
For the second question, the melted or dissolved salt should have easily made its way through the filter paper and into the second container, while the undissolved and muddy sand particles is caught on the filter paper. The size of the pores of the filter paper didn’t change. On the contrary, the size of the salt became smaller because it has been dissolved which is also the reason why it was able to go through the filter paper, while the size of the sand may have doubled or even tripled which made it harder to pass through.