Video Transcript
Manufacturers can mix gold with
copper to make a pink alloy. Which property does this alloying
process enhance? (A) Corrosion resistance, (B)
malleability, (C) chemical purity, (D) luster, or (E) tensile strength.
In this question, we need to
understand how gold changes when manufacturers mix it with copper. Let’s first describe gold
metal.
Gold is a lustrous pure metal
element with the atomic number of 79. It is ordinarily expensive due to
its pleasing esthetic properties and its rarity. Pure gold is considered a noble
metal as it is highly resistant to corrosion and oxidation. Because of these various
properties, gold has been used for thousands of years in currencies. However, pure gold is also highly
malleable and is not suitable for most everyday applications since it deforms
easily. Many manufacturers will combine
pure gold with other less valuable elements to make an alloy with more desirable
properties.
An alloy can be defined as a
metallic solid solution that contains at least two different types of elements. One popular alloy of gold features
copper. The mixture of both gold and copper
atoms in the metallic structure leads to new properties. This alloy usually has a pink, red,
or rose color. It is far less expensive per gram
than pure gold. The alloy is more suitable for
creating jewelry as it is less malleable and less prone to deform when worn. The alloy is harder and stronger
than pure gold. It does tend to be less visually
impressive than pure gold as it does not quite have the same luster and shine. It is also slightly more reactive
than pure gold alone and thus is more prone to corrosion if left in open air.
So the alloying of gold with copper
does not enhance the corrosion resistance, malleability, chemical purity, or
luster. However, it does enhance the
tensile strength of the metal. Therefore, the property that the
alloying process of gold with copper enhances is answer choice (E), tensile
strength.
