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size of gallium is less than aluminium due to d-orbitals,but why so?

Ranjita yadav , 13 Years ago

Grade 11

4 Answers

Ashwin Muralidharan IIT Madras

Hi Ranjita,

The atomic radius of the Ga is less than Al because of poor screening effect.

The atomic radius of Ga is slightly lesser than of Al because in going from Al to Ga, the electrons have already occupied 3d sub shell in Ga. The screening effect of these intervening electrons being poor, has less influence to decrease the effective nuclear charge, therefore the electrons in Ga experience more forces of attractions towards nucleus to result in lower size of Ga than Al.

Regards,

Ashwin (IIT Madras).

Last Activity: 13 Years ago

Karyekar Sunil K

The shielding effect of d-orbitals is very poor due to it’s diffused-spreading-shape in case of gallium. The d-orbital have diffused nature and thus poor shielding-effect.The shielding is just reducing impact of effective positive nuclear charge on the outer most electrons. The position of Gallium is just immediately after Zn which has completly filled d-orbitals ( 10 electrons). This makes the pronunced effect of nuclear charge (Zeff) and we find reduction in atomic radius of Gallium. It is thus diffused d-orbitals and their inability to shield the strong +ve charge which changes the trend of Atomic Radius. The Ga At. radius is thus unexpectedly smaller than Al and change in trend of Periodic Table set-up.

Last Activity: 10 Years ago

Khushwinder Singh

Because the replusions b/w valence electrons and lower sub shell electrons are quite less than that of attraction between valence electrons and nucleus (in Ga). But in Al this phonomenon is just neglected.

Last Activity: 7 Years ago

Yash Chourasiya

Dear Student

The atomic radius of the Ga is less than Al because of poor screening effect.

The atomic radius of Ga is slightly lesser than of Al because in going from Al to Ga, the electrons have already occupied 3d sub shell in Ga.
The screening effect of these intervening electrons being poor, has less influence to decrease the effective nuclear charge, therefore the electrons in Ga experience more forces of attractions towards nucleus to result in lower size of Ga than Al.

I hope this answer will help you.
Thanks & Regards
Yash Chourasiya

Last Activity: 5 Years ago