Question

Which set of elements gives cach of the following alloys: (a) brass; (b) stainless steel; (c) bronze; (d) sterling silver? 1\. Cu, Ag 2\. \(\mathrm{Cu}, \mathrm{Sn}, \mathrm{Zn}\) 3\. Ag. Au 4\. Fe, Cr, Ni 5\. Fe, V 6\. \(\mathrm{Cu}, \mathrm{Zn}\)

Short answer

Brass: 6, Stainless steel: 4, Bronze: 2, Sterling silver: 1

Step-by-step solution

Identify Elements in Brass

Brass is an alloy composed primarily of copper (Cu) and zinc (Zn). Look at the list and find the option that contains these elements. The correct pair is option 6: \(\mathrm{Cu}, \mathrm{Zn}\).

Identify Elements in Stainless Steel

Stainless steel is made from iron (Fe), chromium (Cr), and often nickel (Ni). Look for these elements in the given list. The pair that matches is option 4: \(\mathrm{Fe}, \mathrm{Cr}, \mathrm{Ni}\).

Identify Elements in Bronze

Bronze is an alloy consisting mainly of copper (Cu) and tin (Sn), sometimes with the addition of zinc (Zn). The correct option is 2: \(\mathrm{Cu}, \mathrm{Sn}, \mathrm{Zn}\).

Identify Elements in Sterling Silver

Sterling silver is an alloy made up of silver (Ag) and another metal, usually copper (Cu). From the list, we see that option 1 fits: \(\mathrm{Cu}, \mathrm{Ag}\).

Key concepts

brass composition

Brass is a widely used alloy known for its attractive gold-like appearance and its excellent machinability. It is primarily composed of copper (Cu) and zinc (Zn). The ratio of these two metals can vary, giving brass different properties. For instance, adding more zinc generally increases the strength and ductility of the alloy. Brass is prized for its resistance to corrosion, which makes it ideal for plumbing fittings, musical instruments, and decorative items. It is also a good conductor of electricity, making it useful in electrical applications where both durability and conductivity are required.

stainless steel elements

Stainless steel is a versatile alloy known for its corrosion resistance, which is achieved through the addition of chromium (Cr). The primary elements in stainless steel are iron (Fe), chromium (Cr), and often nickel (Ni). Chromium is crucial as it forms a passive layer of chromium oxide on the surface, preventing rust and corrosion. Nickel is added to enhance the alloy’s toughness and resistance to temperature extremes. Stainless steel is categorized into different grades based on its composition and specific properties. Common uses include kitchen utensils, medical instruments, construction materials, and automotive parts due to its strength and oxidation resistance.

bronze metallurgy

Bronze is one of the oldest alloys known to humankind, historically significant for its use in tools and weapons in the Bronze Age. It is primarily composed of copper (Cu) and tin (Sn). Sometimes, minor amounts of other elements like zinc (Zn), phosphorus (P), or lead (Pb) are added to enhance specific properties. The addition of tin increases the alloy’s hardness and strength while making it more resistant to wear and corrosion. Bronze has a dull gold color and is used in applications such as bearings, clips, springs, statues, and coins. Its excellent load-bearing qualities and resistance to corrosion make it ideal for marine applications.

sterling silver composition

Sterling silver is a popular alloy, primarily composed of silver (Ag) and a small percentage of another metal, usually copper (Cu). Sterling silver is 92.5% silver and 7.5% copper. Adding copper improves the metal’s hardness and durability while maintaining its beautiful luster. Pure silver is too soft for most practical uses, but sterling silver's added hardness makes it ideal for jewelry, cutlery, and various decorative items. It retains the appearance of pure silver while being more resistant to scratching and deformation. Because sterling silver can tarnish due to the presence of copper, regular cleaning and maintenance are necessary to keep its shine.