Question

note that a probability map is not the same as a balloon model
1 is a probability map of a single s orbital in cross - section
2 is a probability map of a single p orbital in cross - section

Explanation:

An s - orbital has a spherical shape. In cross - section, it appears as a circle. A p - orbital has a dumb - bell shape. In cross - section, it has two lobes.

Answer:

1. (b)
2. (a)