Edexcel IGCSE Chemistry 复习笔记 2.5.4 Alloys

• Alloys are mixtures of metals, where the metals are mixed together physically but are not chemically combined
• They can also be made from metals mixed with nonmetals such as carbon
• Alloys often have properties that can be very different to the metals they contain, for example they can have greater strength, hardness or resistance to corrosion or extreme temperatures
• Alloys contain atoms of different sizes, which distorts the regular arrangements of atoms
• This makes it more difficult for the layers to slide over each other, so they are usually much harder than the pure metal
• Brass is a common example of an alloy which contains 70% copper and 30% zinc

Particle diagram showing a mixture of elements in an alloy. The different sizes of the two types of atoms prevent the layers of atoms from sliding over each other, so the alloy becomes less malleable than the pure metal