Question

The electropositive character is the maximum for which of the following elements in group 13?
A. Al
B. B
C. Ga
D. In

Answer 1

Hint: Metal shows more electropositive character as compared to the Non- Metal. The group ‘13’ element is also known as P- block element. Groups are the vertical columns in the periodic table. In a particular group the no. of electrons in the outermost shell remains the same. The members of group 13.

Formula used:
Metal shows more electropositive character as compared to Non- Metal. The group ‘13’ element is also known as P- block element. Groups are the vertical columns in the periodic table. In a particular group the no. of electrons in the outermost shell remains the same. The members of group 13 are Borax, Aluminium, Gallium, Indium, Thallium, with general electronic configuration is $\text{n}{{\text{s}}^{\text{2}}}{{\text{p}}^{\text{1}}}$.

Complete step by step answer:
The electropositive character refers to the metallic behaviour of an element. In the group 13 as we move from the borax to aluminium, the metallic character or electropositive character increases but when we move from aluminium to gallium, indium and thallium, the electropositive character slowly increases. As Al to TI all are typical metals but due to presence of extra d-orbital in Ga, In, TI they experience the shielding effect.
the elements of group 13 a less electronegative or metallic as compared to alkali metals and alkaline earth metals.
Explanation:- Amongst the element of group 13, B has the highest sum of first three ionization enthalpies. As a result, tendency to lose electrons and hence is least electropositive amongst group 13 elements. In other words it is a non-metal and a poor conductor of electricity. However as we move from boron to aluminium the sum of first three ionisation enthalpies decreases due to the increase in atomic size and hence aluminium has a least tendency to lose electrons. Aluminium is a metal and a good conductor of electricity.
Option ‘A’ is correct i.e. Al is most electropositive in group 13 element. Aluminium is silvery white and ductile metal. It is non-magnetic in nature.

So, the correct answer is “Option A”.

Note:
Note that the trends of general characteristics must be known. General characteristics of periodic table are atomic number, density, melting point, Boiling point, Atomic radius, Radius, Ionization Energy, electronegativity, oxidation etc. Here in this question extra d- orbital is present because transition metal comes before Ga, In, TI. Electropositive nature is the tendency to lose electrons.