## Electron Configurations

105114680
Posts: 60
Joined: Fri Sep 28, 2018 12:23 am

### Electron Configurations

I am trying to do the electron configuration for W. Since W is in a row that breaks into the f block I was wondering where I would write the f-electrons. Would they come before or after the d-electrons in an electron configuration?
So far I have it written as: [Xe]6s2 5d4 4f14
Is this correct? If not, could you explain how to determine the order? Thank you.

Jane Burgan 1C
Posts: 73
Joined: Fri Sep 28, 2018 12:15 am

### Re: Electron Configurations

the 4f14 and the 5s4 would come before the 6s2 because they both have lower energy levels than the 6s orbital. When determining the order of the orbitals for the electron configuration think of the orbitals' energy levels. In this case, 4f14 has a lower energy level than 5s2 and 5s4 has a lower energy level than 6s2. So you would get [Xe]4f14 5d4 6s2

Andonios Karas 4H
Posts: 30
Joined: Fri Sep 28, 2018 12:27 am

### Re: Electron Configurations

No, the correct electron configuration for tungsten is [Xe] 4f14 5d4 6s2. You write the electron configuration in order to lowest energies to highest energy shells. A 4f shell is lower energy than a 5d shell. A 5d shell is lower energy than a 6s shell.

First, write the first noble gas with a lower atomic number than the element: [Xe]
Second, fill the correct shells with the Aufbau principle and looking at the periodic table: 2 in the 6s shell, 14 in the 4f shell, and 4 in the 5d shell
Third, order them by increasing number 1, 2, 3, 4, ... : [Xe] 4f14, 5d4, 6s2

If doing the complete electron configuration, order each set with the same integers by type of orbital: s, p, d, and f.