Two groups with opposite trends

Down group 1 the melting points fall; down group 17 the boiling points rise. You will write two tests for a falling and a rising list, check both groups, and find the spread of the halogens' boiling points. Then the program draws both.

The idea. A list falls if every value is lower than the one before it, and rises if every value is higher.

Your tasks.

1. In falls, return True if every value is lower than the one before.
2. In rises, return True if every value is higher than the one before.
3. Find spread, the highest boiling point of the halogens minus the lowest, in kelvin.