Atomic OrbitalsShapes and Energies

Objectives

• When you complete this presentation, you will be able to ...• compare s and p orbitals in terms of their shape• order the s, p, d and f orbitals in terms of ...

• energy• number of possible electrons

Introduction

• The Bohr model of the atom had electrons in circular orbitals around the nucleus.• We were able to find the energy between those

orbitals by using the emission and absorption spectra of atoms.• E = hν, where E is energy, h is Planck’s constant, and ν

is the frequency of the photon emitted or absorbed.

• We saw that the potential energy increases and the difference in energy decreases as we move away from the nucleus.

Introduction

• The Schrödinger Equation describes the position of the electron in terms of total and potential energy.• The equation gives the position as a likelihood - a

probability.• This then leads to the concept of the orbital as an

electron cloud.

• An electron cloud is the volume of space that contains an electron.• Different kinds of clouds are at different

energy levels.

Orbitals

• There are different kinds of orbitals that make up each energy level.• Each energy level is assigned a principal

quantum number.• From 1 to 7• This is the same as the number of periods in the

periodic table.• This is no coincidence.

• Each energy level is called a “shell.”

Orbitals

• The 1st shell contains one orbital:• the 1s orbital.

• The 2nd shell contains two orbitals:• the 2s orbital.• the 2p orbital.

• The 3rd shell contains three orbitals:• the 3s orbital• the 3p orbital• the 3d orbital

Orbitals

• The 4th shell contains four orbitals:• the 4s orbital.• the 4p orbital.• the 4d orbital.• the 4f orbital.

• And, so on.• In actual practice, the 5th shell only contains

four orbitals (the s, p, d, and f orbitals), the 6th shell only contains three orbitals (the s, p, and d orbitals), and the 7th shell only contains two orbitals (the s and p orbitals).

Orbitals

• Each orbital has its own:• shape• number of suborbitals• maximum number of electrons• energy level

Orbital Shapes

• The s orbital has one suborbital and it is shaped like a sphere.

• The s orbital is perfectly symmetrical in all axes.

Orbital Shapes

• The p orbital has three suborbitals and they are shaped like dumbbells.

• Each p orbital is symmetrical to its particular axis.

Orbital Shapes

• The d orbital has five suborbitals and they are shaped like 3D clover leaves.

• Each d orbital is symmetrical to its particular plane.

Orbital Shapes

• The f orbital has seven suborbitals and they are shaped like ... ?

• Each d orbital is symmetric in 3-dimensional space.

Orbital Shapes

• We only need to remember the shapes of the s and p orbitals.

Suborbitals and Electrons

• Each orbital has a specific number of suborbitals available for electrons.• The s-orbital has 1.• The p-orbital has 3.• The d-orbital has 5.• The f-orbital has 7.

• Each of the suborbitals can hold a maximum of 2 electrons.

Suborbitals and Electrons

• Therefore, each orbital has a maximum number of electrons.• The s-orbital has 2 e- maximum (1 orbital × 2

e-/orbital).• The p-orbital has 6 e- maximum (3 orbitals × 2

e-/orbital).• The d-orbital has 10 e- maximum (5 orbitals × 2

e-/orbital).• The f-orbital has 14 e- maximum (7 orbitals × 2

e-/orbital).

Suborbitals and Electrons• This corresponds to the width of each group on the

periodic table.• The s block (Groups 1 and 2) is 2 elements wide.

Suborbitals and Electrons• This corresponds to the width of each group on the

periodic table.• The p block (Groups 13 - 18) is 6 elements wide.

Suborbitals and Electrons• This corresponds to the width of each group on the

periodic table.• The d block (Groups 3 - 12) is 10 elements wide.

Suborbitals and Electrons• This corresponds to the width of each group on the

periodic table.• The f block (lanthanides and actinides) is 14 elements

wide.

Orbitals and Energy

• Each of the orbitals has an energy associated with it.• s-orbitals always have the lowest energy in a shell.• p-orbitals always have the next lowest energy in a

shell.• d-orbitals always have the next lowest energy in a

shell.• f-orbitals always have the highest energy in a shell.

Orbitals and Energy

• We can do a diagram of the estimated energies of the shells and orbitals like this.

1st shell

2nd shell

3rd shell

4th shell

1s2s2p3s3p3d4s4p4d4f

Lower energy

Higher energy Actually, it is a little more complicated than this.

But this gives you a good idea of the energy distribution in the electron shells of an atom.

Orbitals and Energy

• In reality, the upper orbitals of 3rd shell and above are higher energy than the lowest orbital of the next higher shell.

1s2s2p

3s3p3d

4s4p4d4f

En

erg

y

Orbitals and Energy

1s2s2p

3s3p3d 4s

4p4d4f

En

erg

y

5s5p5d

5f

6s6p6d

7s7p

From lowest energy to highest energy:

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7pThis looks complicated.

It would be complicated if we had to memorize this.

But, we don’t.

The periodic table is arranged in just this way.

Orbitals and Energy• We start with 1s.

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p

Orbitals and Energy• We go to 2s.

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p

Orbitals and Energy• Then to 2p.

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p

Orbitals and Energy• Then to 3s.

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p

Orbitals and Energy• Then to 3p.

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p

Orbitals and Energy• Then to 4s.

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p

Orbitals and Energy• Then to 3d.

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p

Orbitals and Energy• Then to 4p.

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p

Orbitals and Energy• Then to 5s.

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p

Orbitals and Energy• Then to 4d.

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p

Orbitals and Energy• Then to 5p.

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p

Orbitals and Energy• Then to 6s.

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p

Orbitals and Energy• Then to 4f.

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p

Orbitals and Energy• Then to 5d.

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p

Orbitals and Energy• Then to 6p.

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p

Orbitals and Energy• Then to 7s.

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p

Orbitals and Energy• Then to 5f.

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p

Orbitals and Energy• Then to 6d.

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p

Orbitals and Energy• And, finally, to 7p.

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p

Orbitals and Energy• To follow the periodic table, we need to remember a

couple of things.• s-orbitals begin in the 1st shell.

➀

Orbitals and Energy• To follow the periodic table, we need to remember a

couple of things.• p-orbitals begin in the 2nd shell.

➀➁

Orbitals and Energy• To follow the periodic table, we need to remember a

couple of things.• d-orbitals begin in the 3rd shell.

➀➁

➂

Orbitals and Energy• To follow the periodic table, we need to remember a

couple of things.• f-orbitals begin in the 4th shell.

➀➁

➂

➃

Orbitals and Energy• If we want to find the orbitals available for an element,

we just follow the periodic table.• For example, for oxygen, O

➀➁

➂

➃

Orbitals and Energy• If we want to find the orbitals available for an element,

we just follow the periodic table.• For example, for oxygen, O, we go 1s

➀➁

➂

➃

Orbitals and Energy• If we want to find the orbitals available for an element,

we just follow the periodic table.• For example, for oxygen, O, we go 1s, 2s

➀➁

➂

➃

Orbitals and Energy• If we want to find the orbitals available for an element,

we just follow the periodic table.• For example, for oxygen, O, we go 1s, 2s, 2p.

➀➁

➂

➃

Orbitals and Energy• If we want to find the orbitals available for an element,

we just follow the periodic table.• Oxygen has electrons in the 2p orbital.

➀➁

➂

➃

Orbitals and Energy• If we want to find the orbitals available for an element,

we just follow the periodic table.• For example, for copper Cu

➀➁

➂

➃

Orbitals and Energy• If we want to find the orbitals available for an element,

we just follow the periodic table.• For example, for copper Cu, we go 1s

➀➁

➂

➃

Orbitals and Energy• If we want to find the orbitals available for an element,

we just follow the periodic table.• For example, for copper Cu, we go 1s, 2s

➀➁

➂

➃

Orbitals and Energy• If we want to find the orbitals available for an element,

we just follow the periodic table.• For example, for copper Cu, we go 1s, 2s, 2p

➀➁

➂

➃

Orbitals and Energy• If we want to find the orbitals available for an element,

we just follow the periodic table.• For example, for copper Cu, we go 1s, 2s, 2p, 3s

➀➁

➂

➃

Orbitals and Energy• If we want to find the orbitals available for an element,

we just follow the periodic table.• For example, for copper Cu, we go 1s, 2s, 2p, 3s, 3p

➀➁

➂

➃

Orbitals and Energy• If we want to find the orbitals available for an element,

we just follow the periodic table.• For example, for copper Cu, we go 1s, 2s, 2p, 3s, 3p,4s

➀➁

➂

➃

Orbitals and Energy• If we want to find the orbitals available for an element,

we just follow the periodic table.• For example, for copper Cu, we go 1s, 2s, 2p, 3s,

3p,4s, 3d.

➀➁

➂

➃

Orbitals and Energy• If we want to find the orbitals available for an element,

we just follow the periodic table.• Copper has electrons in the 3d orbital.

➀➁

➂

➃

Orbitals and Energy• We don’t need to use the whole table if we remember

where to start our count (s at 1, p at 2, d at 3, and f at 4).

• For example, lead, Pb:

➀➁

➂

➃

Orbitals and Energy• We don’t need to use the whole table if we remember

where to start our count (s at 1, p at 2, d at 3, and f at 4).

• For example, lead, Pb: 2p

➀➁

➂

➃

Orbitals and Energy• We don’t need to use the whole table if we remember

where to start our count (s at 1, p at 2, d at 3, and f at 4).

• For example, lead, Pb: 2p, 3p

➀➁

➂

➃

Orbitals and Energy• We don’t need to use the whole table if we remember

where to start our count (s at 1, p at 2, d at 3, and f at 4).

• For example, lead, Pb: 2p, 3p, 4p

➀➁

➂

➃

Orbitals and Energy• We don’t need to use the whole table if we remember

where to start our count (s at 1, p at 2, d at 3, and f at 4).

• For example, lead, Pb: 2p, 3p, 4p, 5p

➀➁

➂

➃

Orbitals and Energy• We don’t need to use the whole table if we remember

where to start our count (s at 1, p at 2, d at 3, and f at 4).

• For example, lead, Pb: 2p, 3p, 4p, 5p, 6p.

➀➁

➂

➃

Orbitals and Energy• We don’t need to use the whole table if we remember

where to start our count (s at 1, p at 2, d at 3, and f at 4).

• Lead has electrons in the 6p orbital.

➀➁

➂

➃

Summary

• There are different orbitals that make up each energy level.• Each level is assigned a principal quantum

number from 1 to 7• Each level is called a “shell.”• Each orbital has its own shape, number of

suborbitals, maximum number of electrons, and energy level.

Summary• We only need to remember the shapes of the s

and p orbitals.

• Each orbital has a specific number of suborbitals available for electrons, the s-orbital has 1, the p-orbital has 3, the d-orbital has 5, the f-orbital has 7.

• Each of the suborbitals can hold a maximum of 2 electrons.

Summary• Therefore, each orbital has a maximum number

of electrons: the s-orbital has 2 maximum, the p-orbital has 6 maximum, the d-orbital has 10 maximum, and the f-orbital has 14 maximum.

• Each of the orbitals has an energy associated with it: s-orbitals always have the lowest energy in a shell, p-orbitals always have the next lowest energy in a shell, d-orbitals always have the next lowest energy in a shell, and f-orbitals always have the highest energy in a shell.

• The periodic table is arranged in a way to be able to tell how the energies of orbitals and shells are arranged.