Answer: The correct answer is Option 2.
Explanation:
Nuclear charge is defined as the positive charge that is experienced by an electron in an atom having more than 1 electrons.
More the number of protons present in an atom, more is the nuclear charge.
Atomic number is defined as the number of protons that are present in an atom.
For the given options:
Atomic number of aluminium = 13
Atomic number of argon = 18
Atomic number of silicon = 14
Atomic number of sodium = 11
As, argon has more number of protons in its nucleus, it will experience greatest nuclear charge.
Hence, the correct answer is Option 2.
