While moving in a period from left to right,Atomic size decreasesNuclear charge increasesI.E increasesAll of the above

All of the above.

1. Atomic Size Decreases: As we move from left to right in a period, the number of protons in the nucleus increases. This increases the positive charge of the nucleus which pulls the electrons closer to the nucleus, thereby decreasing the atomic size.

2. Nuclear Charge Increases: The nuclear charge is the total charge in the nucleus of an atom. As we move from left to right in a period, the number of protons (which carry a positive charge) increases. Therefore, the nuclear charge increases.

3. Ionization Energy Increases: Ionization energy is the energy required to remove an electron from an atom. As the atomic size decreases, the electrons are held more tightly by the nucleus. Therefore, more energy is needed to remove an electron, which means the ionization energy increases.

So, all of the above statements are correct.