Acold front moves through and the temperature drops by 20 degrees. in which temperature scale would this 20 degree change represent the largest change in temperature?

In the Celsius scale each degree is one part of 100 degrees. This is because in this scale the difference between boiling and freezing temperatures of water is 100 ° - 0 ° = 100 °, so one degree Celsius is one part of 100.

In the Farenheit scale, each degree is one part of 180 degrees. This is because in this scale the difference between the boiling and freezind temperatures are 212 ° - 32 ° = 180°, so one degree Farenheti is one part of 180.

That means that 1 °C is a larger amount than 1 °C, so 20°C is a larger amount than 20°F.

Conclusion: 20 degree change represents a larger change in Celsius scale.