What is the term that describes an object's mass per unit volume?

In the image, the arrow is pointing to a celestial object. which attribute disqualifies the object from being a planet?

In a vernier instrument the main scale is in 1/2 mm divisions .vernier is made by redividing 19 such divisions into 20 equal parts. calculate the least count of the instrument.

True or false graphs must include scales that increase by the same amount