Where the rise breaks

You will find, with pandas alone, the elements of periods 2 and 3 whose first ionisation enthalpy falls below the element before, and the mean of each block.

The idea. df.groupby("period")["ie"].diff() gives the change from the element before, inside each period. A negative change is a break. groupby("block")["ie"].mean() gives the mean of each block.

Your tasks.

1. Add a column rise: the change from the element before, inside each period.
2. Set breaks to the list of symbols whose rise is below zero.
3. Set block_mean to a dictionary of the mean ionisation enthalpy of each block, rounded to one place.