In science class, Jonathan added a small amount of sand to a beaker of water. He stirred it vigorously so that all the sand swirled around in the water. Jonathan then claimed to his classmates that he had made a solution. However, his teacher told Jonathan that he was mistaken. Why was the teacher correct? Jonathan made a compound, not a mixture

A solid substance cannot dissolve in water to form a solution

The sand will eventually settle to the bottom and will not dissolve in the water

A chemical reaction did not take place, so a solution was not formed

Answer is (D) A chemical reaction did not take place.

What Jonathan created was a mixture.

For cyclohexane compounds drawn in a chair conformation:   -axial bonds are vertical  -equatorial bonds are parallel to two bonds within the ring.  thus, as i assume the chair conformation is drawn:   -the x group is in an axial position, as are the five other vertical bonds.  -three axial bonds are on the top face of the ring  -the other three axial bonds are on the bottom face  the position of the second substituent on each ring carbon is equatorial.  gauche groups must be on an adjacent carbon such as carbon 6 and carbon 2, and also gauche groups are rotated by 60 degrees relative to each other.  drawing the newman projections for c1–c2 and c1–c6 aids in visualizing the groups that are gauche to the y group on c1.  click this link and watch some academic videos that may you more understand the topic 

Ci hope  it  you