Answer:
Step-by-step explanation:
Range = Highest value - Lowest value
A 'soft solder' melts between 183 °C and 212 °C.
Melting range of a 'soft solder' =
A 'hard solder' melts between 620 °C and 680 °C.
Melting range of a 'hard solder' =
So,
Difference in melting ranges = Melting range of a 'hard solder' - Melting range of a 'soft solder' =