Question

Which one of the following is not a metalloid?
A.Boron
B.Silicon
C.Gallium
D.Germanium

Answer 1

We need to know that the metalloid is an element which has the properties of both solid non – metals and metals, which means it acts as an intermediate between these semiconductors or solid non – metals and metals. The metalloids are also known as semimetals. The metals are occupied in the first two rows of the periodic table and the non – metals are occupied at the right side of the periodic table.

Complete answer:
We have to know that the boron is a chemical element having the symbol $'B'$ with atomic number five. And the boron is an example of metalloid. Hence, option (A) is incorrect.
Silicon is a chemical element having the symbol $'Si'$ having the atomic number $14$. And silicon is an example of metalloid. Hence, option (B) is incorrect.
Gallium is a chemical element having the symbol $'Ga'$ with atomic number $31$. And the gallium is not an example of metalloid and it is a post – transition metal. The gallium is occupied between the metalloids and the transition metal of the periodic table and it has some of the characters of transition metals. And it becomes liquid at above room temperature. Hence, option (C) is correct.
The germanium is a chemical element having the symbol with atomic number $32$. And it is not an example of metalloid. Hence, option (D) is incorrect.

Hence, option (C) is correct.

Note:
We need to know that the metalloid is the chemical element having the chemical properties of both metals and non – metals. And it has metallic characters, but the metalloids are brittle and it conducts electricity. And chemically the metalloid behaves as non – metals. When the metal is reacting with metals, there is a formation of alloys. And the chemical properties and physical properties of metalloids are intermediate in nature.