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Aaron Turpen

Why does the Na+ ion have a smaller radius than the Na atom?

Bhavesh  Follow

As you know the atomic number of Na atom is 11.But when he lose one electron there left 10 electrons in its shells. 2 electrons in his k-shell and 8 electrons in his valance shell. By losing his valance shell electron it becomes stable because by octal rule ( when an atom has 8 electrons in his valance shell it become stable) and its attraction of Nucleus and valance shell become very strong . This decreases the size of atom . That’s the reason Na + ion has small radious than the Na atom.

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Donald Emily  Follow

Neon (Ne) has a bigger radius. In a neutral neon atom, there are 10 protons and 10 electrons. In a sodium ion there are 11 protons and 10 electrons. Since there is a larger proton to electron ratio, there is more pull from the positively charged protons on the electrons, pulling then closer to the nucleus and reducing atomic radius of the sodium ion.

Hope this answers your question.

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Andrei Tancau  Follow

Atomic number of sodium is 11 so it's configuration is 2,8,1. So there is one electron in the outermost shell.when this electron is removed to form sodium ion,one shell is removed thereby reducing the size.

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Ashwin Adhikari  Follow

Yes Na+ is smaller than Na because Na+ is formed when an electron is lost from the Na atom,Thus the effective nuclear charge increases bcz the number of protons exceeds the number of electrons .This results in bringing the valence shell a little closer to the nucleus because of a very strong nuclear pull.

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Bill Burniece  Follow

Atomic number of sodium,Na,is 11. Thus,it has 11 protons which pull the 11 electrons outside the nucleus. This is called the effective nuclear charge.

In case of Na+ ion,there are only 10 electrons outside the nucleus. Hence,the same pull of the protons are experienced by a fewer number of electrons i.e. the effective nuclear charge on the electrons is increased. Hence,because of relatively greater pul,they are drawn more towards the nucleus,thereby having a smaller radius than Na in it’s ground state.

Hope this helps!

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Antoni Worthers  Follow

Because as the atom becomes charged, in this case positively, the repulsion between electrons decreases and so the net attraction between them and protons rises, providing a lower value of the atom’s radius.

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Bishal Bhadra  Follow

Cl- is much more bigger than Na+. Because,

1) Na+ has two filled shells, whereas Cl- has three filled shells.

2) Effective nuclear charge of cation is greater than anion.

3) Extra shell causes more shielding effect.

Hope this helps.

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Asif Makhdoomi  Follow

[math]Mg^{2+}[/math] denotes the charge of the magnesium cation. I’m not sure what [math]Mg^{+2}[/math] is supposed to mean. I guess you mean [math]Mg^{+II}[/math] which indicated an oxidation state of magnesium, for example as a centre ion in a complex.

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