1. The force that keeps the nucleons bound inside the nucleus of an atom A. Strong electrostatic force
B. Strong nuclear force
C. Strong centripetal force
D. Gravitational attraction

2.The amount of energy needed to split the nucleus into individual protons and neutrons
A. Nuclide transfer energy
B. Nuclear binding energy
C. Mass energy equivalence
D. Nuclear energy
3. The difference between the mass of the nucleons and the mass of an Atom
A. Mass of nucleus
B. Mass defect
C. Atomic mass
D. Isotopic mass

1). strong nuclear force 2). nuclear binding energy 3), atomic mass  

Explanation:

1). The force that keeps nucleons together is known as nuclear force. This is a strong force with gravity playing a very minor role in this. 2). Nuclear binding energy is the energy needed to divide the nucleus of an atom into protons and neutrons. Mass deficiency is the difference between the expected mass and the real mass of the nucleus of the atom. The binding energy of the device will appear as an extra mass, which is the reason for this discrepancy. 3). Atomic mass is the weighted average mass of the element atom dependent on the relative natural abundance of the isotopes of that element. The mass number is the sum number of protons and neutrons in the nucleus of the atom.

hope this helped!

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

i believe the answer is true.