Answer:
effective nuclear, electron shielding and coulumbic attraction
Step-by-step explanation:
Effective nuclear charge is the attractive positive charge of nuclear proton acting on valence electron.
Electron shielding refers to the blocking of valence shell electron attraction by the nucleus due to the presence of inner-shell electrons
Coulombic Attraction is the electrostatic attraction between two charged particles. Often when discussing periodic trends the charged particles are the nucleus (specifically the total number of protons) and the electrons. Often we are referring to the outermost electrons, the valence electrons.