Lesson: Electron Configuration

Electron Configuration

by William Lovering

Multiple Choice

What atom matches this electron configuration? 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰

• Zinc

• Copper

• Nickel

• Germanium

Multiple Choice

The electron configuration of an atom is 1s²2s²2p⁶.  The number of electrons in the atom is 

• 3

• 6

• 8

• 10

Multiple Choice

Which electron configuration belongs to Chlorine (Cl)?

• 1s² 2s² 2p⁶ 3s² 3p⁵

• 1s² 2s² 2p⁶ 3s² 3p⁶

• 1s² 2s² 2p⁶ 3s² 3p⁷

Multiple Choice

How many electrons can the d sublevel hold?

• 14

• 10

• 2

• 6

Multiple Choice

How many electrons can the s sublevel hold?

• 14

• 10

• 2

• 6

Multiple Choice

Energy levels are denoted by:

• letters

• coefficient

• superscripts

• subscripts

Multiple Choice

What is this element?

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶

• Argon

• Krypton

• Selenium

• Bromide

Multiple Choice

All 3 noble gases ended with different energy levels but the same sublevel.

• True

• False

Multiple Choice

Was the p subshell in noble gases full?

• Yes

• No

​Noble Gas Configuration

​Example: If I needed to do the configuration for Gold (Au).

​Gold has 79 electrons. Going backwards, the closest noble gas is Xenon with 54 electrons.

​Xenon ends with 5p⁶ . I need to place 25 more electrons (79-54).

​

​Following the energy order, 6s comes after 5p. So I start there, placing the 25 electrons.

​

[Xe] 6s² 4f¹⁴ 5d⁹

Multiple Choice

What would be the next term if we increased the configuration of Neon by 1 electron?

• 3s¹

• 2d¹

• 3s²

• 3p¹

​Noble Gas Configuration

​All noble gases (except Helium) end with Np⁶.

​

​We can use this to shorten electron configurations.

​

​Krypton is atomic number 36. It has 36 electrons. Its configuration ends with 4p⁶. This means we know that the first 36 electrons will end with 4p⁶.

​

​If we wanted to find the configuration of strontium (Sr), notice it has 38 electrons. The first 36 will occupy all the subshells up to 4p⁶ then we only need to add 2 more electrons to get to 38. After 4p⁶ is 5s. Place the 2 electrons to make it 5s² and that would be how strontium ends.

Multiple Choice

Choose the Noble Gas that you would use to begin the shorthand configuration of the following element.

Iron

• [He]

• [Ne]

• [Ar]

• [Kr]

Multiple Choice

Choose the Noble Gas that you would use to begin the shorthand configuration of the following element.

Plutonium (Pu)

• [Xe]

• [Ne]

• [Rn]

• [Kr]

Multiple Choice

Choose the correct shortcut configuration for iodine.

• [Ar]4s²4d¹⁰4p⁵

• [Kr]5s²4d¹⁰5p⁵

• [Xe]5s²5d¹⁰5p⁵

• none of the above

Multiple Choice

Identify the Electron Configuration for Aluminum (Al)

• 1s² 2s² 2p⁶ 3s² 3p¹

• 1s² 2s² 2p⁶ 3s² 3p³

• 1s² 2s² 2p⁶ 3s² 4p¹

Multiple Choice

What is the shorthand configuration for Tin?

• [Xe]5s²4d¹⁰5p²

• [Xe]5s²4d¹⁰5p²

• [Kr]5p²

• [Kr]5s²4d¹⁰5p²