Question

Which one of the following is a metalloid?
(A) Bi
(B) C
(C) Ge
(D) Pb

Answer 1

Hint: To solve this question try to refer to the electronic configuration of the given elements and then try to distinguish whether the element is a metal, a nonmetal or a metalloid.

Complete answer:
We have been provided with elements: Bi, C, Ge and Pb,
And we need to find the metalloid among these,
So, for that first we will talk about the metals, nonmetals and metalloids,
Metals: We know that metals have a shiny appearance, they are hard, are good conductors of heat and electricity, form basic oxide and can donate electrons.
Non-metals: when we talk about non-metals, they have some opposite properties from that of metals, as they are soft, don’t have a shiny surface, are not a good conductor of heat and electricity, form acidic oxide and accept electrons.
Metalloid: they are the chemical element which has both the properties of metals and non-metals,
The first element is Bi that is bismuth with the atomic number 83,
So, the electronic configuration of Bismuth would be: $\left[Xe\right]4f^{14}5d^{10}6s^{2}6p^3$,
Also, bismuth has a shiny surface and a yellowish tinge, forms a basic oxide,
From which we can say that bismuth is a metal.
The next element that we have is C that is carbon with atomic number 6,
So, the electronic configuration of carbon would be: $1s^{2}2s^{2}2p^2$,
Also, carbon forms covalent bonds, acidic oxides, it is non-malleable and ductile and it is soft in the form of graphite,
From which we can say that carbon is a non-metal.
The next element that we have Ge that is germanium with the atomic number 32,
So, the electronic configuration of germanium would be: $\left[AR\right]3d^{10}4s^{2}4p^2$,
Also, germanium is a semiconductor as it has electrical conductivity between insulator and conductor, it does not react with oxygen, it is stable in air and water, it is hard, lustrous, grey-white, brittle,
From which we can say that germanium is a metalloid.
The last element which we have is Pb that is lead with atomic number 82,
So, the electronic configuration of lead would be: $\left[Xe\right]4f^{14}5d^{10}6s^{2}6p^2$,
Also, lead is highly malleable, ductile, form basic oxide,
From which we can say that lead is a metal.
So, from all this we can say that out of all these germanium is a metalloid,

From this we can conclude that the correct option is (C).

Note:
The best way of finding that the given element is metalloid is to first refer to its properties so that we can find if there is any element which resembles properties of both metal and non-metal.