Why is diamond said to be hard

Diamond is said to be the hardest element because it is unbreakable by humans. These diamonds are mined, and they are very hard. A miner knows when they have found diamond when they feel something super hard.

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Conduction is the transfer of thermal energy through direct contact. Convection is the transfer of thermal energy through the movement of a liquid or gas. Radiation is the transfer of thermal energy through thermal emission.

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