Question

Amongst the elements $B,{\rm{ }}Al,{\rm{ }}C$and $Si$ the element having most metallic character is:
(A) $Al$
(B) $C$
(C) $B$
(D) $Si$

Answer 1

If more number of electrons are present in the last shell of the element then it is non-metallic.
The elements that have as minimum as the number of atoms in the last shell then it is more metallic in nature.

Complete step-by-step answer: Boron is an element having symbol B and atomic number $5$. Its group is $13$ and it belongs to $p - block$ in periodic table. Its electron configuration is given as:
$1{s^2}2{s^2}2{p^1}$
Al stands for aluminium and its atomic number is $13$. It is anciently derived from potassium aluminium sulphate. It is lightweight and found in the group $13$in the periodic table and belongs to block - $13$. There is single electrons in last orbit of aluminium molecule according to configuration structure since it has 13 electrons according to its atomic number it have configuration as:
$1{s^2}2{s^2}2{p^6}3{s^2}3{p^1}$
C stands for Carbon and its atomic number is $6$. It belongs to group number $14$in the periodic table and belongs to the p-block element. It has $2$electrons available to make covalent bonds. So we can say that it is tetravalent in nature. Hence it is non-metallic in nature.
Its electron configuration is given as:
$1{s^2}2{s^2}2{p^2}$
SI stands for silicon and its atomic number is $14$. It belongs to family group $14$ [IVa] of the periodic table. Hence it belongs to $p - block$ in the periodic table
Its electron configuration is:
$1{s^2}2{s^2}2{p^6}3{s^2}3{p^2}$
Hence it has two electrons in the outermost shell of the silicon.
The elements that have as minimum as the number of atoms in the last shell then it is more metallic in nature.
Hence, we can see the last orbit of Boron has a single electron and aluminium also has a single electron in the last shell; both are metallic but the atomic number of aluminium is more than the atomic number of boron . Hence aluminium is obviously more metallic than boron.

Hence option (A) is the correct answer.

Note: The metallic character depends upon tendency to lose the electrons,as atomic size increases,tendency to lose the electron increases and hence metallic character increases.The metallic character is associated with high melting points. When electrons are present in the valence shell of a metal, metallic bonds are formed and higher is the melting point.