Barrons SAT Subject Test Chemistry, 13th Edition

(C) An s-type orbital has a spherical probability distribution for the electrons
in that energy state. Energy level 3 represents a higher energy than energy
levels 1 or 2; therefore, the 3s orbital is larger than the 1s or 2s orbitals. The
higher the energy of the electrons, the farther away the electrons will likely be
found from the nucleus.