How do the mass and height of an object affect the gravitational potential
energy?

Explanation:

The bigger the mass and the higher the height of the object above earth’s surface, the bigger the potential energy. The potential energy can be evaluated using the formula below;

P.E. = m*g*h, where

m = mass in kilograms,

g = the acceleration due to gravity (9.8 m / s² at the surface of the earth), and

h = height in meters.

From the formula, it is clear that increasing mass, gravity or/and height will give an increased potential energy

the answer is na (sodium)