Na+is smaller than Na atom because:a)The effective nuclear charge is greater in case of sodium ion.b)Nucleus in each case contains different nucleons.c)Na+ is more stable than in Na atom.d)Sodium atom has one electron lesser than sodium ion.Correct answer is option 'A'. Can you explain this answer?

Question

Answer

In this question option a is given correct but in NCERT it is given that in case of cation nuclear charge remains same.
guys please explain...

Answer

In sodium and sodium ion, nuclear charge will remain same but the distribution of that charge will be different in both the case.
In sodium ion nuclear charge per electron will be greater than that in sodium atom ( as no. of electrons in Na+ is less than the no. of electrons in Na)
So due to greater nuclear charge, size of Na+ will be small than Na.

Answer

Bcoz Na+ has greater effective nuclear charge than Na

Answer

When Na+ is formed it loses an electron due to which screening effect decreases and hence effective nuclear charge increases. (also when Na+ is formed as it loses one electron it  achieves the configuration of Ne. which means it has one shell less.)

Answer

In case of Na ..11 electrons are binded by the coulombic force of attraction ...thus the force gets distributed between 11 electrons...but in case of Na ion 10 electrpns are present so the coulombic force of attraction gets divided between 10 electrons hence the  force is greater for sodium ion and size is smaller

Answer

Effective nuclear charge:
The effective nuclear charge refers to the net positive charge experienced by an electron in an atom. It is determined by the number of protons in the nucleus and the shielding effect of other electrons.

Nuclear charge in Na atom and Na ion:
In a neutral sodium (Na) atom, the number of protons in the nucleus is equal to the number of electrons orbiting around it, which is 11. However, in the sodium ion (Na+), one electron has been removed, resulting in a net positive charge of +1. Thus, the number of protons in the nucleus remains the same, 11, but the number of electrons decreases to 10.

Effect on effective nuclear charge:
The effective nuclear charge experienced by an electron is influenced by the attraction between the negatively charged electrons and the positively charged nucleus. The more electrons there are, the greater the shielding effect and the lower the effective nuclear charge experienced by each electron.

When an electron is removed to form a sodium ion, the number of electrons decreases, resulting in reduced electron-electron repulsion. As a result, the remaining electrons are not shielded as effectively by the reduced number of electrons. Therefore, the effective nuclear charge experienced by each electron increases.

Comparison between Na atom and Na ion:
In the case of sodium (Na) atom:
- The effective nuclear charge experienced by each electron is lower due to greater electron-electron repulsion caused by the 11 electrons.
- The atom is electrically neutral, with 11 protons and 11 electrons.

In the case of sodium ion (Na+):
- The effective nuclear charge experienced by each electron is higher because there are only 10 electrons to shield the attraction from the 11 protons in the nucleus.
- The ion has a net positive charge of +1, with 11 protons and 10 electrons.

Conclusion:
The effective nuclear charge is greater in the case of the sodium ion (Na+) compared to the neutral sodium (Na) atom. This is because the removal of one electron reduces the electron-electron repulsion, resulting in a higher effective nuclear charge experienced by each remaining electron.

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