What are alloys? Name an important alloy which contains some of the lanthanoid metals. Mention its uses.
An alloy is a blend of metals prepared by mixing the components. They may be homogeneous solid solutions in which the atoms of one metal are distributed randomly among the atoms of the other. Alloys are hard and often have high melting points.
An important alloy containing lanthanoid metals is mischmetall. It consists of a lanthanoid metal (approximately 95%) and iron (approximately 5%), along with traces of S, C, Ca, and Al.
Mischmetall is used in Mg-based alloy to produce bullets, shells, and lighter flints.
Explanation
The answer is derived directly from Section 4.3.14 for the definition of alloys and the paragraph preceding Section 4.6 for the specific alloy 'mischmetall'. The textbook defines alloys as blends of metals formed by mixing, often forming homogeneous solid solutions. It identifies mischmetall as a key lanthanoid alloy (95% lanthanoid, 5% iron) and lists its uses in manufacturing bullets, shells, and lighter flints.