Question

Write an orbital diagram for the ground state of iron atom (Z=26) and phosphorus atom
(Z=15)

Answer 1

Explanation:

The electronic configuration for first 19 electrons of Fe will be 1s2 2s2 2p6 3s2 3p6 4s1.

The 20th electron enters 4s subshell.

The 20th electron enters 4s subshell.So, n=4

The 20th electron enters 4s subshell.So, n=4For s-orbital ⇒l=0

The 20th electron enters 4s subshell.So, n=4For s-orbital ⇒l=0magnetic quantum no. ⇒m=0

The 20th electron enters 4s subshell.So, n=4For s-orbital ⇒l=0magnetic quantum no. ⇒m=0Spin quantum no. ⇒s=− 1/2

Hence, the four quantum numbers n, l, m, and s of 20th electron of Fe (Z = 26) ion would be 4,0,0,− 1/2 respectively.

Answer 2

The Orbital diagram for the ground state of an Iron atom (Z=26) and phosphorus atom (Z=15) is having electrons in the outermost orbital and it follows AUFBAU's RULE.

Explanation:

• Orbital diagram for the ground state of an iron atom (Z=26)

• Electronic configuration will be 1s²,2s²,2p⁶,3s²,3p⁶,3d⁵,4s¹.

• Orbital diagram for the ground state of the Phosphorous atom (Z=15).

• Electronic configuration will be 1s²,2s²,2p⁶,3s²,3p³

• The arrangement of electrons around the nucleus of an atom with a lower energy level is the statement as per AUFBAU's RULE.
• After 4s is full the remaining electron enters into the 3d orbital.
• Thus in the electronic configuration for an atom like Fe, the 3d is usually written 4s.