Final answer:
Copper, lead, and zinc are commonly used in soldering alloys. While copper and zinc are also used in other alloys like brass and bronze, aluminum is not typically used in solder due to its unsuitable properties. so, option a, c and d are correct.
Step-by-step explanation:
The metals used in solder alloys typically include copper (Cu), lead (Pb), and zinc (Zn). Copper is known for its excellent electrical conductivity, making it a staple in various alloys, including the electrical solder. Lead has historically been included in soldering alloys due to its low melting point and good flow properties. However, due to health concerns over lead exposure, lead-free solder alloys often replace lead with other metals, such as silver, bismuth, or zinc. Zinc serves as an important alloying material due to its resistance to corrosion and its ability to lower the melting point of the resulting alloy.
Aluminum (Al) is generally not used in solder due to its oxide layer and higher melting point, which can hinder bonding processes. Alloys such as brass (copper and zinc) and bronze (copper and tin) showcase the versatility of copper as a constituent in metal mixtures, often providing superior properties compared to pure metals. For example, bronze is harder than copper and brass is notably malleable, making it useful in many applications, including musical instruments.