Question

Why are metals hard \[?\]
A. They have free electrons
B. They gain electrons easily
C. They are held by weak forces
D. All of the above

Answer 1

Hint: Generally metals are hard in nature. We will discuss their hardness and then go through each option. Due to the hardness of metals they are used in construction work mostly. Metals generally form metallic bonds with other atoms which are strong enough to break.

Complete answer: Metals are those substances which can conduct electricity easily through them. The reason behind conduction of electricity is the number of free electrons present in them. Due to the presence of these large numbers of free electrons, they not only help in conduction of electric current but they make it harder. Actually in metal atoms, there is a large number of free electrons present inside it. These free electrons create a pressure which is known as electron pressure. This electron pressure can be in the order of \[{10^5}{\text{ atm}}\]. Such a large amount of pressure is required to crush them which is not an easy task. Therefore to crush them a pressure greater than internal pressure is required which is quite hard. The bending of these metal atoms is due to dislocation of electrons at some place inside the crystal structure of metal atoms. Metal atoms lose electrons easily to form stable compounds in nature. They always form metallic bonds which are quite strong.
Hence the correct option is A.

Note:
Metals have a tendency to lose electrons and to become cation. This is because the valence electrons of metal atoms are always less than four. Metal atoms are held by strong forces of attraction which are quite large to break easily. They are brittle and sound in nature too.