Draw atomic orbital diagrams representing the ground-state...

Key Concepts

Pauli Exclusion Principle

The Pauli Exclusion Principle states that no two electrons in an atom can have the same set of four quantum numbers. This principle limits the number of electrons that can reside in a single orbital to two, with opposite spins.

Hund's Rule

Hund's Rule instructs that electrons will fill degenerate orbitals (orbitals of the same energy) singly first, with parallel spins, before pairing up. This minimizes electron repulsions and stabilizes the atom.

Aufbau Principle

The Aufbau Principle is the guideline used for building up the electron configuration of an atom. It states that electrons fill the lowest energy orbitals available before moving to higher energy orbitals, ensuring a stepwise increase in energy.

Unpaired Electrons

Unpaired electrons are electrons that occupy an orbital alone without a matching electron of opposite spin. The number and arrangement of unpaired electrons determine important properties such as magnetism and reactivity.

Electron Configuration

Electron configuration is a method of describing the arrangement of electrons in an atom’s orbitals. It indicates how electrons are distributed among the available orbitals in order of increasing energy, providing key insights into the element's chemical properties and reactivity.

Atomic Orbitals

Atomic orbitals are regions in an atom where electrons are most likely to be found. They are defined by a set of quantum numbers and have distinct shapes and orientations (such as s, p, d, and f orbitals), which reflect the probability distribution of the electron’s location.

Ground-State

The ground state of an atom is the lowest energy configuration of electrons. In this state, electrons are arranged in the orbitals in a way that minimizes the overall energy of the atom following specific filling rules and principles.

Transcript

00:01 So the first step is to go to the periodic table and find the elements that we're looking for so we know how many electrons they have.

00:08 So starting with sodium, if we look at the periodic table, we find that sodium in a is number 11.

00:19 So it has 11 e minus electrons.

00:23 So now let's write our orbital diagram out.

00:25 We always start with the 1s and we go to the 2s we go to the 2b 2p, which can fit six electrons and after that we have the 3s.

00:39 So let's fill this in and so they always need to have opposite spins.

00:50 So that's four electrons.

00:58 That's seven.

01:00 Eight, nine, ten, eleven.

01:05 Okay.

01:06 And always remember your huns rule and your poly exclusion principle when filling these in.

01:10 So you do them in the correct order.

01:12 Remember that, like i did, you always need to fill with the spin in one direction first.

01:20 And you also need to fill in.

01:23 Each blank should only have one electron at first.

01:26 And then you go back and add in the second paired electrons.

01:32 That's to minimize energy repulsion from the electrons.

01:39 Okay, now for co, let's go ahead and find that on the periodic table.

01:47 Cobalt is number 27.

01:56 So 27 electrons is going to give us a large diagram, but we still go in the same order.

02:31 But now instead of directly jumping to the 4p, we are actually going to go to the 3d, and that is because the d the d is actually lower in energy than the p so once we hit that row the row that cobalts in you need to start putting the ds before the p's and it's the 3d because it's always in minus one for the d so now we fill these in up down 1 two three four remember the order 5, 6, 7 all in different ones and now we come back and pair them 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 18, 19, 20.

03:27 Running out of the room, but 21, 22, 23, 24, 25...

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