Structure and Properties of Materials：練習題

Which statement correctly describes why graphite can conduct electricity while diamond cannot?

An alloy is generally harder and stronger than the pure metal from which it is derived. Which statement best explains this property in terms of structure?

Explain why graphite is able to conduct electricity while diamond cannot.

Explain, in terms of structure and bonding, why sodium chloride has a high melting point whereas methane has a very low melting point.

Define the term isotopes in terms of sub-atomic particles.

Substances can be classified as elements, compounds, or mixtures based on their composition and properties.

(a) Describe one difference between a compound and a mixture in terms of their composition. (1 point)

(b) Brass and stainless steel are examples of alloys.
(i) Define the term alloy. (1 point)
(ii) Explain why alloys like brass are generally harder and stronger than the pure metals from which they are made. (1 point)

A metal specimen X is thought to be an alloy of copper and zinc.
(a) Describe the structure of a pure metal and explain why it is malleable.
(b) Explain, in terms of its structure, why the alloy X is stronger and harder than pure copper.
(c) State the name of the common alloy made from copper and zinc.