Electron configurations of ions | Atomic structure and properties | AP Chemistry | Khan Academy

TL;DR

This video explains how to determine the electron configuration of ions, using examples of a negatively charged fluoride ion and a positively charged calcium ion.

Transcript

• [Instructor] In many videos we have already talked about electron configuration and now in this video we're going to extend that understanding by thinking about the electron configuration of ions. These are going to be charged atoms. Let's just start looking at some examples. Let's say we are dealing with fluorine. Now, we know what a neutral flu... Read More

Key Insights

• 😑 Electron configuration describes the arrangement of electrons in an atom or ion.
• 😐 Negatively charged ions have an additional electron compared to their neutral atom.
• 😐 Positively charged ions have fewer electrons compared to their neutral atom.
• 😐 The electron configuration of an ion can be determined by modifying the electron configuration of the corresponding neutral atom.

Questions & Answers

Q: How do you determine the electron configuration of a negatively charged ion?

To determine the electron configuration of a negatively charged ion, you start with the electron configuration of the corresponding neutral atom and add one more electron to the sub-shell that has space for it.

Q: What is the electron configuration of a fluoride anion?

The electron configuration of a fluoride anion is 1s2, 2s2, 2p6, which means it has gained one electron in the 2p sub-shell compared to a neutral fluorine atom.

Q: How do you determine the electron configuration of a positively charged ion?

To determine the electron configuration of a positively charged ion, you start with the electron configuration of the corresponding neutral atom and remove the highest energy electrons from the sub-shell.

Q: What is the electron configuration of a calcium cation with a positive charge of two?

The electron configuration of a calcium cation with a positive charge of two is the same as argon, which is [Ar]. Two electrons are removed from the 4s sub-shell.

Summary & Key Takeaways

• The electron configuration of a neutral fluorine atom is 1s2, 2s2, 2p5.

• The electron configuration of a fluoride anion, which has one extra electron, is 1s2, 2s2, 2p6.

• The electron configuration of a neutral calcium atom is [Ar] 4s2.

• The electron configuration of a calcium cation with a positive charge of two is the same as argon: [Ar].