Write the ground state electron configuration for each atom and ion pair. a. Zr, Zr^2+ b. Co, Co

Write the ground state electron configuration for each atom...

Key Concepts

Orbital Energy Ordering in Transition Metals

Transition metals exhibit a unique orbital energy ordering where, despite the d-orbitals being filled after the s-orbitals in neutral atoms, the energy levels can change upon ionization. This reordering must be taken into account when writing electron configurations for transition metal ions, ensuring that electrons are removed from orbitals with the highest principal quantum number first.

Ground State Electron Configuration

This concept involves the arrangement of electrons in an atom or ion in its lowest energy state. It serves as the fundamental basis for understanding an element's chemical behavior and reactivity, and it is determined by the principles governing electron distribution among atomic orbitals.

Electron Removal in Ions

When atoms form positive ions, electrons are removed from the highest energy orbitals first. In transition metals, this often means that electrons are taken from the s-orbital before the d-orbital, even if the d-orbital is filled later in the neutral atom. This removal order is essential for writing the correct electron configurations for ions.

Aufbau Principle

The Aufbau Principle states that electrons occupy the lowest energy orbitals available before moving to higher energy ones. This principle guides the sequential filling of orbitals and is crucial for constructing the electron configuration of atoms and ions in their ground states.

Transcript

00:01 In these problems, we're asked to write the electron configuration for different atoms and their ions.

00:07 So to start, part a has zinc and zinc 2 plus ion.

00:11 So zinc we can find here on the periodic table.

00:15 And the way we're going to write electron configurations is we're going to read the periodic table, top bottom, left, right.

00:20 So first, find the noble gas that comes before zinc.

00:25 So if zinc is number 30, argon is the previous noble gas.

00:30 So we're going to start out by writing argon.

00:38 And then we're going to read, like i said, top bottom, left, right.

00:41 So starting here in the 4s block and then followed by the d block.

00:47 So we have two electrons in 4s.

00:52 So we're going to write 4s2.

00:58 And then we have 10 electrons in the 3d level, all of these.

01:04 So we would write that as 3d10.

01:13 Now, your instructor or your textbook or whatever it is that is assigning these problems to you may ask you to write these in a different order, like writing the ds first because their principal energy level number is three, followed by the 4s2.

01:29 It really doesn't matter, but whatever way you're asked to do it, follow that direction.

01:34 Now, when we take a metal ion, we need to lose the s electrons first.

01:39 The electrons and the s orbitals first.

01:41 So for zinc that is losing the 4s2 electrons.

01:48 So for zinc 2 plus the electron configuration is argon followed by 3d.

01:59 So for zinc we have this electron configuration for zinc 2 plus we have the other electrical configuration.

02:15 Next we're going to look at cobalt and cobalt 2 plus.

02:17 So as we did before, we're going to find cobalt on the periodic table.

02:23 That's right here.

02:25 Excuse me.

02:26 That is right here, number 27.

02:29 So we're going to start with argon again and then see that there's two electrons in the 4s level.

02:38 And then all of these, that's one, two, three, four, five, one, two, three, four, five, six, seven electrons in the three d level...

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