Electron Configurations 2021

Electron Configurations 2021

by Christine Campbell

Multiple Choice

The energy levels that are highest in energy are _________ the nucleus.

• closest to

• farthest from

​Aufbau Diagram - know this!

​What this tells you:

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​1. which energy levels hold which sublevels

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​2. the filling order for electron configurations. lowest energy 1s gets filled first.

​Pauli Exclusion Principle

​An atomic orbital may contain at most 2 electrons

• To occupy the same orbital the electrons must have an opposite spin (clockwise or counterclockwise)

• Use arrows to designate its spin 🡹🡻

​Hund's Rule

• One electron enters each orbital until all the orbitals contain one electron with the same spin direction

• Electrons occupy orbitals of the same energy in a way that makes the number of electrons with the same spin direction as large as possible.​

Open Ended

How many orbitals are in s, p, d, and f sublevels?

s-

p-

d-

f-

​Steps for Writing Electron Configurations

1. Analyze – Identify the relevant concepts, atomic number/number of electrons (i.e. Phosphorous – 15 electrons)

2. Place electrons in the orbital with the lowest energy first (1s), then continue placing electrons in each orbital with the next higher energy. (1s²2s²2p⁶3s²3p³)

3. The superscripts should add up to the number of electrons. ​

​Orbital Filling Diagrams

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Open Ended

The following electron configuration belongs to which element? Explain how you got your answer.

1s²2s²2p⁶3s²3p⁵

Open Ended

Write the electron configuration for Gallium.

​

​

Multiple Choice

What atom matches this electron configuration?
1s²2s²2p⁶3s²3p⁶4s²3d¹⁰

• Zinc
• Copper
• Nickel
• Germanium

Multiple Choice

How many electrons can the first energy level hold?

• 1
• 2
• 8
• 0

Multiple Choice

How many half-filled orbitals would silicon contain?

• 0
• 2
• 1
• 3

​Abbreviated Electron Configurations

• ​Let's try Zirconium

Multiple Choice

What is the abbreviated electron configuration for silver?

• 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d⁹
• [Kr] 5s² 4d⁹
• [Ar] 4s² 3d⁹
• [Ag]