Why Gallium is smaller than aluminium?

Answer 1

Beryllium - II Group , 2nd perod

Gallium - 13th group , 4th period

Since gallium has 4 shells, it has lesser nuclear charge than beryllium.

Now, as the nuclear charge decreases, electropositivity increases.

So, gallium is more electropositive.

Hence it is more metallic.

PS : You may think that beryllium is more metallic because it is located on the left side of the period. But, the number of shells plays a more important role than the number of valence electrons in determining the metallic character.

well gallium is more metallic but its not that the shells have more part to play in determining it, it actually comes down to the effective nuclear charge,is the valence electron in a s or p sub-shwll electron and all

Answer 2

Yes. In normal cases, a period 3 element would have a smaller atomic radius than a period 4, but there are exceptions to periodic trends. (forgive the advanced chemistry jargon) The electrons in the "d" subshell are poor shielders as a result of the elongated rosette structure of the subshell. When Aluminum's electrons become excited, they spread out into the "d" subshell without much attraction from the nucleus, therefore increasing the atomic radius. Gallium's nucleus contains more protons, and is able to attract the middle electrons, while the "d" electrons remain in the 3rd energy level, further away from the nucleus, reducing its atomic radius.

Answer 3

Both the sodium ion and the aluminum ion have the same electron configuration (1S22S22P6). However, aluminum has a greater number of protons and therefore a greater positive charge in its nucleus than sodium. This exerts a greater force of attraction on the electrons and pulls them into a smaller radius than in sodium.

Answer 4

No. Down the group ionisation enthalpy decreases

Answer 5

Gallium is smaller than aluminum because the ionization enthalpy decreases. It decreases due to an increase in atom size.

Answer 6

yeah