Chapter 5 – Models of the Atom

• Do Now – Current Events and Chemistry

• Objective – Chap 4 Review 5.1 Models of the Atom

• Homework – Pg. 132 # 1-6

Supersonic Man

How does this relate to anything we have talked about already this year?

Write you idea in your notes

Tevatron

CERN Super Collider

Review Questions – Pg 125 # 1-9

Review Questions – Pg 125 # 1-9

1. C2. A3. B4. B5. 96. E7. False, True8. True, False 9. True, True – Correct explanation

Review what we know

Democritus

Dalton

Thompson

Rutherford

The Bohr Model

Carbon

Magnesium

Silicon

Fluorine

Do Now –Draw Bohr Models of K, O, and Ar Any old work to turn in?

Objective – 5.1 and 5.2 The Quantum Mechanical Model

Homework – Pg 136 # 10-13

The Electron Cloud Model

Where is the propeller?

The Quantum Mechanical Model

• The Quantum Mechanical Model determines the allowed energies an electron can have and how likely it is to find the electron in various locations around the nucleus.

Atomic Orbitals

• Atomic Orbitals are thought of a regions of space around a nucleus where a given electron is likely (90%) to be.

• Do Now – Check neighbor’s homework and give an effort grade of √-, √, √+

• Objective – Electron Configuration in Atoms

• HW - Pg 136 # 10-13

Pg 132 # 1-6 1. It couldn’t explain why metals give of characteristic colors when heated or explain the chemical properties of elements.2. An electron is found only in a specific path or orbital around the nucleus3. It determines allowed energies and where it is likely to be located. 4. The have different shapes. 5. By gaining or losing a quantum of energy.6. In an atom, electrons have certain fixed energy levels. To move to a different level requires the emission or absorption of an exact amount of energy or quantum. The energy of the electron is said to be quantized.

• Calculations• • Average Mass • Total Mass (g) / Number in Sample = Average Mass (g)• A-Regular 15.10 g / 17 = .8882g • B-Peanut =2.6078g • C-Pretzel =2.4417g• Total =1.7861g• • Relative Abundance • Number in Sample / Total Number of Particles = Relative Abundance • A-Regular 17 / 38 =0.4474• B-Peanut = 0.2368• C-Pretzel = 0.3158• Total = 1.0• • Percent Abundance • Relative Abundance x 100 = Percent Abundance• A-Regular 0.4474 x 100 = 44.737 %• B-Peanut =23.68 %• C-Pretzel = 31.58 %• Total = 100 %

Review of 5.1

Principal Number ofEnergy Levels Sublevels Orbitals

1 1 1 s (1 orbital)

2 2 2 s (1 orbital), 2 p (3 orbitals)

3 3 3 s (1 orbital,) 3 p (3 orbitals), 3 d (5 orbitals)

4 4 4 s (1 orbital,) 4 p (3 orbitals), 4 d (5 orbitals), 4 f (7 orbitals)

Chlorine has 17 electrons 1s2 2s2 2p63s23p5

Electron Configuration

• How atoms are arranged to get the most stable atom possible.

Three Rules 1. Aufau Principle 2. Pauli Exclusion Principle 3. Hund’s Rule

Aufbau Principle

Electrons will occupy the orbitals of the lower energy levels first.

Pauli Exclusion Principle

An orbital may describe 2 electrons, in other words, orbitals can hold 2 electrons If two electrons occupy the same orbital they must have opposite spins ↑↓

Hund’s Rule

Electrons will occupy orbitals of the same energy level in such a way that make the spin direction as large as possible.

In other words, every orbital at the same energy level gets one electron before any get a second

Exceptions to the Configuration Rules

What do you think would happen if an atom were to differ from the configuration rules?

There are small differences between the 3d and 4s energy levels and even smaller differences between the 5f and 6d levels

Friday, October 8th

• Do Now – Review Homework WorksheetGet out your copy of the periodic table

• Obj – Physics and the Quantum Mechanical Model

• HW – Pg. 146 # 16 – 19 Lab Handout Part 1

Zinc 1s22s22p63s23p64s23d10

Magnesium 1s22s22p63s2

3p3 There are 3 electrons in the p sublevel of the 3rd energy level.

• Neon 8A – Nobel Gas 2nd period

• Argon 8A – Nobel Gas 3rd period

• Vandium 5B – 4th period

Do Now – Get out the pre lab you wrote

Objective – 5.3 Physics and the Quantum Mechanical Model

HW – Pg. 146 # 16-20

Light

Amplitude

Wavelength (λ)

Frequency (v)

Hertz (Hz)

C = λ v

The speed of light is the product of the wavelength and the frequency.

Light is electromagnetic radiation

Atomic Spectra

• When atoms absorb energy, the electrons move to a higher energy level. These electrons lose energy by emitting light when they return to a lower energy level.

The frequencies emitted are unique for different elements and

combinations of elements

The light emitted by an electron moving from a higher energy level to a lower (not always ground) has a frequency directly proportional to the energy change of the electron.

Spectrum

Atomic Spectrum

Quantum Mechanics

Heisenberg Uncertainty Principle

It is impossible to know exactly both the velocity and position of a particle (electron) at the same time.

Flame Test Lab

• Do Now – Pre-labs out with pen/pencil and calculator. All bags away and table clear.

• Obj – Flame Test Lab

• HW – Pg. 153 # 1-18

Calculations

∆E = h c λ (note that this is in m and not nm)

Calculations

∆E = h c λ (note that this is in m and not nm)

You need to convert from nm to m.

Calcium was orange with frequency of 600nm600 nm · 1 m = 1 x 109 nm can you do

this ?

Understand Scientific Notation

600 x 1/ 1 x 109 Means move decimal 9 places to the right. Think about how little of a meter you will have if you only have 600 nm.

000000000000600.0000000 move 9 places .000000600 m or 6.0 x 10-7

Understand Scientific How to Use Your Notation Calculator

600 x 1/ 1 x 109 600 x 1/ 1 x 109 Means move decimal 9 places to the right. Think about how 600 1 1 EE 9little of a meter you will have if you only have 600 nm. 0r 000000000000600.0000000 move 9 places 600 1 10 9 .000000600 m or 6.0 x 10-7 = 6 E -7 or 6.0x 10-7

2nd

˄