Question

Why are alloys such as this sometimes more practical than pure samples of metals?

• A. The smaller atoms in this alloy increase its malleability and ductility.
• B. The smaller atoms in this alloy form a softer solid.
• C. The smaller atoms in this allow form a rigid structure.
• D. The smaller atoms in this alloy decrease the density of the pure substance.

Answer 1

The correct option is C The smaller atoms in this allow form a rigid structure.

One reason that manufacturers combine pure metals to form alloys is to change the physical properties of the metals. Pure metals may be too soft to hold up to regular use, but alloying them makes them tougher. As a pure metal, gold bends and stretches so easily that it would quickly pull out of shape if it were formed into a ring and worn on the finger. Jewelry manufacturers alloy pure gold with silver, copper or zinc to improve the metal's durability and rigidity. The gold contributes its color and resistance to corrosion; the other metals contribute their strength. The result is a 14-karat gold ring that withstands daily wear.

The compact structure given in the figure will resist the layers from moving over each other and that will make it a rigid structure.

So the correct answer is C.