Which of the following are correct statements? Check all that apply.
A. The number of protons in an atom's nucleus defines what kind of
atom it is.
B. Atoms are the basic units of matter.
C. The atomic number is the number of electrons an atom has.
D. The number of neutrons an atom has defines what kind of
element it is.

Ben (55kg) is standing on very slippery ice when junior (25kg) bumps into him. junior was moving at a speed of 8 m/s before the collision and ben and junior embrace after the collision. find the speed of ben and junior as they move across the ice after the collision. give the answer in m/s. describe the work you did to get the answer.