What are the constituents of Solder alloy? Which property of Solder makes it suitable for welding electrical wires?

The constituents metals of solder alloy are lead (Pb) and tin (Sn).

Alloys are solid mixtures of two or metals. They are generally more useful compare to a normal metal. This is because of their special chemical and physical properties.

For example, the alloy of lead and tin is called solder which is mainly used in welding electrical wires. This is because of its low melting point and good conducting nature, it is used to join wires to leads of components such as switches and printed circuit boards.