The highest sequence for this shell is the number 2, preceding both the s and p in the diagram. This means that the outermost shell is the second level shell. In this shell, there are 7 electrons, 2 in the 2s orbital and 5 in the 2p orbital.
As a side note (not sure if this is a typo), the electron structure for fluorine begins with a 1s2, not a 1s1.
