Question

# Solder is an alloy of:A. 70 % Pb, 30% SnB. 33 % Pb, 67% SnC. 80 % Pb, 20% SnD. 90 % Cu, 10% Sn

A solder is a fusible metal alloy with a melting point or melting point range of $90 - 450^\circ C$, used in a process called soldering where it is melted to join metallic surfaces. It is especially useful in electronics and plumbing. Alloys that melt between $180^\circ$and $190^\circ C$ are the most commonly used alloys. Solder is an alloy of tin and lead. The alloy of tin and lead have characteristic weight percentages. Ideally, solder is $63$ percent tin and $37$ percent lead.