Describe characteristics of a wave (wavelength, frequency, energy) Explain how wave characteristics are related Explain how light and different colors

Chapters 4 & 5: Learning Targets

Describe characteristics of a wave (wavelength, frequency, energy)

Explain how wave characteristics are related Explain how light and different colors of light are produced Define the electromagnetic spectrum Explain Bohr models including their advantages and disadvantages Determine the electron configuration and/or orbital diagram of any

atom or ion; use these to determine groups, periods and identities of elements along with things such as number of unpaired electrons

Define the periodic trends and be able to compare to elements and explain their difference with regards to these trends

Describe the role of probability in orbital theory Determine if an ion for a given element will be a cation or anion

and explain how each type of ion is formed

Chapters 4 & 5: Key Words

Ground state Excited state Wavelength Frequency Energy Photon Electromagnetic

spectrum Energy level Orbital Valence electron electron configuration

Core electron Alkali metal Alkaline earth metal Halogen Actinide Lanthanide Atomic radius Ionization energy Electronegativity Transition element Main-group element

Section 1: Properties of Light

Pages 91-97 RBQs #1b,1c,6,8 For a chemical reaction to occur, the atoms and/or molecules involved must physically collide with each other

If two atoms react, which part of the atoms will interact with each other first?

The structure and arrangement of _________________________ therefore, is the key to understanding chemical reactivity


Pages 91-97 RBQs #1b,1c,6,8 The arrangement of electrons was determined by studying how atoms absorb and emit electromagnetic radiation, e.g. light

EM radiation is one way that energy travels through space


Pages 91-97 RBQs Page 118 #1b,1c,6,8 EM radiation has 3 characteristics: speed, wavelength, and frequency

The speed of light (c), is a constant for all forms of EM radiation in a vacuum

We will always assume that EM radiation is movingthrough a vacuum

c = 3.0 x 108 m/s

Section 1: Properties of LightPages 91-97 RBQs Page 118 #1b,1c,6,8

The 2nd characteristic of waves is wavelength (λ) Wavelength is the distance between two peaks


Frequency (ν) indicates how many peaks pass a given point each second and is the 3rd characteristic


Frequency (ν) indicates how many peaks pass a given point each second and is the 3rd characteristic


The characteristics are related by the following equation:

Be careful with units! Make sure everybody matches up!

Given that c is a constant, what kind of relationship does this show between wavelength and frequency?


The energy of the radiation is also related to the frequency of the radiation

The fun part is that light behave like a wave, but it also shows behaviors characteristic of particles, in this case called photons

The equation below gives the energy of EM radiation, and is equal to the energy of one single photon; QUANTIZED!

Calculate the frequency of light with a wavelength of 6.50 x 102 nm. Also, determine the unit.A. 1.95 x 1011

B. 4.61 x 105

C. 1.95 x 102

D. 4.62 x 1014

What is the increment of energy (the quantum) that is emitted at 4.50 x 102 nm? Determine the unit, also.A. 4.42 x 10-19

B. 4.42 x 10-28

C. 8.95 x 10-32

D. 1.01 x 1048


Atoms are normally found in their ground state, which is the lowest energy state of an atom

When an atom absorbsenergy, for example from electricity, the atom entersthe excited state

When the atom is excited, theelectrons move to higher levels


Excess energy makes the atom unstable, and the excess energy is released as a photon (light) to return the atom to the ground state


White light contains every wavelength of visible light, and products a continuous spectrum

Other times, only certain wavelengths are emitted producing a line spectrum


Substances emit different wavelengths because they absorb and emit different amounts of energy due to differing numbers and arrangements of electrons

Each substance has its own unique line spectrum

These can be used to identifyunknown substances


Niels Bohr used the idea that electrons can only possess certain amounts of energy to develop the Bohr model; this model showed electrons traveling in fixed, circular orbits

Sadly, Bohr was wrong…atoms with more than one electron blowthis idea to tiny little pieces

But atoms and electrons beingquantized was pretty frickin’ smart of him

Section 2: OrbitalsPage 100

A key development in understanding the structure of the atom was Schrodinger’s wave equation, which lead to quantum mechanics...Heisenberg helped a little, too...

Solving this equation leads to a series of wave functions, which is essentially a set of x, y, and z coordinates

Each point graphed as a result of these coordinates indicates the possible location of an electron


Graphing a lot of these points gives a map of the probable location of an electron; the exact location of an electron is pretty much impossible to determine

Each point gives a possible electron location; more dotsmeans a higher probability of an electron being there

The area of space in which an electron is most likely to be found is called an orbital


This is done for every electron they can get their hands on, for example p-orbitals

Notice that there are three ways the p-orbital can be oriented in space…this means there can be three p-orbitals!! Sweet!


And d-orbitals…


And f-orbitals…just to blow your mind!


Each orbital (or area of space) can hold a maximum of 2 electrons.

One or more orbitals combine to make sublevels or subshells

The sublevels consist of different shapes of orbitals, and are designated using letters

The four different shapes of orbitals are s, p, d, and f

So an f-sublevel consists of f-orbitals, a d-sublevel consists of d-orbitals and so on…


Something to help clarify this is to think of an atom as a hotel

If the atom is a hotel, each energy level is a floor of the hotel

The sublevels are different types of rooms on that floor

The orbitals are the individual rooms on each floor

Each room (orbital) has a maximum occupancy of 2 people (electrons)

Section 3: Electron ConfigurationsPages 105-107, 110-116, 128-133 RBQs Pages 118-120 #17, 22-30, 36,

37, 40, 43, 45More RBQs Pages 155-158 #6-13a, 14a, 16a, 27-31, 39, 41, 43, 46,49

Electron configurations and orbital diagrams are used to show the location (probable) of electrons in an atom

Electron configurations use the notation seen below:

Orbital notation looks like this fun stuff down here:

Section 3: Electron ConfigurationsPages 105-107, 110-116, 128-133 RBQs Pages 118-120 #17, 22-30, 36, 37, 40, 43,

45More RBQs Pages 155-158 #6-13a, 14a, 16a, 27-31, 39, 41, 43, 46,49

Electron configurations and orbital notations are determined by applying the relationship between the periodic table and the structure of atoms (which you figured out in your lab)

Let’s find the e- configuration and orbital notation for oxygen...and while we’re at it, say hello to Pauli and Hund!

Section 3: Electron ConfigurationsPages 105-107, 110-116, 128-133 RBQs Pages 118-120 #17, 22-30, 36, 37,

40, 43, 45More RBQs Pages 155-158 #6-13a, 14a, 16a, 27-31, 39, 41, 43, 46,49

Now how about iron?

And what about bromine?



And lets try neodymium (atomic #60) ?

And for fun, lead!



What is incorrect about orbital notation below?



What is incorrect about orbital notation below?

Which element is represented by the electron configuration

seen below?

A. VanadiumB. ArgonC. IronD. Cobalt

Which element does this orbital notation represent?

A. ChlorineB. FluorineC. OxygenD. Neon

What element does the orbital notation represent?

A. VanadiumB. PhosphorousC. OxygenD. Sulfur



Noble gas notation gives a way of shortening the electron configuration and focusing on valence electrons

Element

Electron Configuration Noble Gas Config.

Sodium 1s2s2p63s1 [Ne] 3s1

Argon 1s22s22p63s23p6 [Ne] 3s23p6

Silicon 1s22s22p63s23p2 [Ne]3s23p2

Fluorine 1s22s22p5 [He] 2s22p5

Beryllium

1s22s2 [He] 2s2

Iron 1s22s22p63s23p64s23d6 [Ar] 4s23d6

Lead 1s22s22p63s23p64s23d104p65s24d105p66s25d104f146p2

[Xe] 6s25d104f146p2



Based on the noble gas configurations on the previous slide, write steps to use in determining the noble gas configuration of an element.

The noble gas configuration below is that of which

element?

A. NiB. PdC. PtD. Ag

[Kr] 5s24d8



The electron configurations of ions are determined by keeping track of the number of electrons gained/lost and exactly where they are added to or removed from

Metals lose electrons forming positively charged ions called cations

Metals lose electrons from the highest energy level



Nonmetals gain electrons forming negatively charged ions called anions

Nonmetals gain electrons in the highest energy SUBlevel



Write the electron configuration and noble gas configuration for the nitride ion, N3-.

Write the electron configuration and noble gas configuration for the Cadmium ion, Cd+2.

Section 4: Periodic Properties and TrendsPages 140-146, 149-154 RBQs Pgs 156-158 #17-20, 22-26, 32, 33, 35-

38, 45

The structure of the atom, as reflected in the periodic table, can be used to determine and predict various properties of atoms

Ionization energy: the energy required to remove an electron from a gaseous atom or ion

Atomic Radius: Half the distance between the nuclei of two atoms

Electronegativity: the ability of an atom in a molecule to attract shared electrons

With each property, it is all about how strongly the nucleus of the atom attracts valence electrons; two factors impact this


38, 45

Coulomb’s Law illustrates these two factors:

F = electrostatic force q = electric charge r = distance between charge centers k = who cares?


38, 45

So think about this in terms of an atom:


38, 45

The charge factor is about more than just the number of protons in the nucleus

The focus is on the nucleus attracting the valence electrons, so the core/inner shell/shielding electrons must be considered


38, 45

The core electrons cause the shielding effect

Core electron cause a decrease in the amount of attractive pull felt by the valence electron(s)

More core electrons = larger decrease

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=f4NtNLGDQLjijM&tbnid=W5i3FGfGqk0gBM:&ved=0CAUQjRw&url=https://www.boundless.com/chemistry/periodic-properties/electron-configuration/the-shielding-effect-and-effective-nuclear-charge/&ei=59VlUumBHIOp2QXvqIDwAg&bvm=bv.55123115,d.b2I&psig=AFQjCNFdCw79zFHIFpBXpwwNzhWoZjaMpQ&ust=1382491864515510


38, 45

This is summed up by the effective nuclear charge(Zeff)


38, 45

Find the Zeff for the following elements; then describe how the Zeff changes moving from top to bottom within a group


38, 45

Find the Zeff for the first four elements below; then describe how the Zeff changes moving from left to right within a period


38, 45

Distance between the nucleus and the valence electrons is all about the number of energy levels

More energy levels means valence electrons farther from nucleus


38, 45

Distance between the nucleus and the valence electrons is all about the number of energy levels

More energy levels means valence electrons farther from nucleus


38, 45

So when comparing two elements in a period, which factor causes them to have different properties? Which is ignored?

And when comparing two elements in the same group, which factor causes them to have different properties? Which is ignored?


38, 45

Section 4: Periodic Properties and TrendsPages 237-246 RBQs #3, 4, 8, 10, 15-43

Ionization energy is the energy needed to remove a valence electron

Does a high ionization energy mean an atom has a strong attraction for its valence electron(s) or a weak attraction?

Ionization Energies


Which has a higher ionization energy: lithium or fluorine? Explain.

Which has higher ionization energy: lithium or potassium? Explain.


Electronegativity is the ability of an atom to attract shared electrons when bonded to another atom


Electronegativity Values


Which has a greater electronegativity: lithium or fluorine? Explain.

Which has a greater electronegativity: lithium or potassium? Explain.


38, 45

Atomic radius is defined as half the distance between the nuclei in a molecule consisting of identical atoms

More simply, the atomic radius can be thought of as the size of an atom

Since the boundary of an atom can’t be defined, we can’t just measure from one side of an atom to another


38, 45

Which atom is larger: lithium or fluorine? Explain.

Which atom is larger: lithium or potassium? Explain.


Changes that occur with ions can be determined similarly; draw a Bohr model for a neutral lithium atom and an lithium ion below. Describe how their radii differ and why this difference exists.


Now do the same for a Bohr model for a neutral fluorine atom and a fluoride ion below. Describe how their radii differ and why this difference exists. They are not the same size!!!


And now draw a fluoride ion, and oxide ion, and a sodium ion. Arrange them from smallest to largest, and explain the order selected.

Arrange the following by increasing atomic radius:

Ca, Ni, Br?A. Ni, Br, CaB. Br, Ca, NiC. Ca, Br, NiD. Ca, Ni, BrE. Br, Ni, Ca

Arrange the following in order of increasing ionization energy: F,

Br, IA. I, Br, FB. Br, I, FC. F, Br, ID. I, F, BrE. Br, F, I

And now increasing electronegativity: N, Rb, Ca

A. N, Rb, CaB. Ca, Rb, NC. Rb, N, CaD. N, Ca, RbE. Rb, Ca, N

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Describe characteristics of a wave (wavelength, frequency, energy) Explain how wave characteristics are related Explain how light and different colors