A scientist wants to estimate the mass of an atom. What information can be used to do this?

A. The masses of the electrons and neutrons can be added together.
B. The atomic number of the element can be used.
C. The masses of the protons and neutrons can be added together.
D. The column number of the periodic table can be used.

jupiter is the largest planet in our solar system, having a mass and radius that are respectively, 318 and 11.2 times that of earth. suppose that an object falls from rest near the surface of each planet and that the acceleration due to gravity remains constant during the fall. each object falls the same distance before striking the ground. determine the ratio of the time of fall on jupiter to that on earth.