Which of the following best explains why diamonds are very hard?
a. diamonds are made up of several different isotopes of carbon.
b. diamonds are made up of several different allotropes of carbon.
c. the atoms in a diamond are arranged in a rigid crystalline structure.
d. the atoms in a diamond are arranged in flat sheets that are tightly bonded.

Respuesta :

The best and most correct answer among the choices provided by the question is the third choice, c. the atoms in a diamond are arranged in a rigid crystalline structure. 
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Answer: Option (C)

Explanation: Diamond is the hardest element and it is because the carbon atoms are linked with one another by a strong covalent bond, forming an unbreakable crystalline structure. Covalent bonds are formed when atoms share electrons with each other.

According to the Mohr's hardness scale, diamond has hardness of 10, being the hardest of all. It is denoted by C and it crystallizes in the isometric system and its durability is very high.

Diamonds are found in the kimberlite pipes, where the kimberlite rocks are located at a great depth having extreme pressure condition.

Diamonds are often used in the jewelries.

Thus, the correct answer is option (C).