Elements

Electron configuration of Yttrium (Y)

Read the Yttrium electron configuration, noble-gas shorthand, valence shell, orbital filling logic, and the mistakes to avoid when writing Y.

Guide: Guía práctica Read: 5 min Updated: 2026-07-07

Element guide

Electron configuration of Yttrium (Y)

The electron configuration of Yttrium is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d1 5s2. In shorthand form it is written as [Kr] 4d1 5s2.

Use this page to connect the notation with atomic number 39, the d-block, and the valence pattern 4d1 5s2.

How to write the configuration

Configuration at a glance

Yttrium has atomic number 39, so a neutral atom has 39 electrons. The configuration 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d1 5s2 is a compact record of where those electrons sit by subshell.

The shorthand [Kr] 4d1 5s2 replaces the filled inner core with the previous noble gas. That notation keeps attention on the electrons that usually explain bonding, ions, and periodic trends.

Step-by-step filling

After the krypton core (36 electrons), 3 more electrons need placement. The 5s subshell receives 2 electrons (5s2), and the remaining 1 electron goes into the 4d subshell (4d1).

Step-by-step filling walkthrough: 1. Start with atomic number 39. 2. Fill through krypton: 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 (36 electrons). 3. Fill 5s2 (38 electrons total). 4. Place 1 electron in 4d (39 electrons total). 5. The single 4d electron gives Yttrium one unpaired electron.

Orbital diagram and valence meaning

Yttrium has one unpaired electron in the 4d subshell, which contributes to its common +3 oxidation state. As a group 3 element, Yttrium typically loses all three valence electrons (4d1 5s2) to form Y3+.

The valence clue for Y is 4d1 5s2. For transition metals, both the 5s and 4d electrons participate in bonding.

Common mistakes

The first mistake is miscounting: after krypton (36), 5s2 (38), 4d1 (39). Verify: 2+2+6+2+6+10+2+6+1+2 = 39. The second mistake is confusing Yttrium with Ytterbium (Yb, atomic number 70), which has a very different configuration.

A third common error is forgetting that Yttrium is a transition metal, not a main-group element. Its 4d1 electron is a valence electron, not a core electron.

Yttrium reference table

Item Value
Atomic number 39
Full configuration 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d1 5s2
Noble-gas notation [Kr] 4d1 5s2
Valence clue 4d1 5s2
Block d-block

Use the table as a learning reference, then verify advanced oxidation-state questions with your course material.

Before you submit an answer

  • The superscripts add up to 39 for a neutral Yttrium atom.
  • The notation follows the filling order used in your course.
  • The last occupied subshell matches the periodic-table block.
  • Any transition-metal or actinide exception is checked against a reference.
  • The shorthand core is a noble gas, not a random previous element.

Common questions

What is the electron configuration of Yttrium?

The neutral Yttrium atom is written as 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d1 5s2. The shorthand form is [Kr] 4d1 5s2.

How many valence electrons does Yttrium have?

Start from the outer-shell clue 4d1 5s2. For transition metals, inspect both s and d electrons carefully. Yttrium has 3 valence electrons.

Should I memorize this configuration?

Memorize the filling pattern first. Individual configurations become easier when you can rebuild them from atomic number, noble-gas cores, and periodic-table position.

What is the common oxidation state of Yttrium?

Yttrium commonly forms Y3+ by losing all three valence electrons (4d1 5s2), giving it a noble-gas configuration of [Kr].

Study notes and practice checks

From answer to understanding

Yttrium is a group 3 transition metal with properties similar to the lanthanides. Its electron configuration [Kr] 4d1 5s2 is chemically significant because it determines that Y3+ is the dominant ion.

Practice comparison

Compare Yttrium (Y) with Scandium (Sc) and Zirconium (Zr). Sc: [Ar] 3d1 4s2, Y: [Kr] 4d1 5s2, Zr: [Kr] 4d2 5s2. The pattern shows a clean d-subshell filling across group 3 to group 4 in period 5.

Teacher and self-study notes

Yttrium is often grouped with the rare-earth elements due to similar chemical behavior. The single 4d electron makes Y paramagnetic in its metallic form, though Y3+ compounds are diamagnetic.

Elena Marquez

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Elena Marquez

Chemistry educator and study-guide editor

Elena explains electron configurations, orbital diagrams, and periodic trends for learners who need clear steps before memorization. Her guides focus on counting, notation, and common classroom mistakes.

Credenciales: Editorial specialization in introductory chemistry, periodic trends, and student reference material.

Experiencia: More than eight years preparing practical chemistry explainers, worksheets, and reference material for independent learners.

Actualizado: 2026-07-07 Politica editorial Correcciones

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