Question

part a
se
express your answer in condensed form in order of increasing orbital energy as a string without blank space between orbitals. for example, he should be entered as he2s^22p^2.
part e
sn
express your answer in condensed form in order of increasing orbital energy as a string without blank space between orbitals. for example, he2s^2

Explanation:

Step1: Find Se's atomic number

Selenium (Se) has atomic number 34.

Step2: Identify noble gas core

The preceding noble gas is Argon (Ar, atomic number 18).

Step3: Fill remaining orbitals

Fill orbitals in energy order: $4s^2$, $3d^{10}$, $4p^4$.
Combine core and valence orbitals: $[Ar]4s^23d^{10}4p^4$

Step4: Find Sn's atomic number

Tin (Sn) has atomic number 50.

Step5: Identify noble gas core

The preceding noble gas is Krypton (Kr, atomic number 36).

Step6: Fill remaining orbitals

Fill orbitals in energy order: $5s^2$, $4d^{10}$, $5p^2$.
Combine core and valence orbitals: $[Kr]5s^24d^{10}5p^2$

Answer:

Part A: $[Ar]4s^23d^{10}4p^4$
Part B: $[Kr]5s^24d^{10}5p^2$