Choose the correct answer to complete the paragraph about the acceptance of the heliocentric model. In the second century BCE, the Greek astronomer Ptolemy tried to explain the backward movement of the planets by using a solar system model that included ... For centuries, this was the accepted model. During the Renaissance, Nicholas ... discovered the old heliocentric model of Aristarchus. In Aristarchus’s model, the rising and setting of the Sun was explained by the movement of the...

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 

The correct answer would be b) volume versus temperature, because they are also directly proportional.