chapter 5: electrons in atoms. 5.2 electron arrangement in atoms when an electron goes to a higher...
TRANSCRIPT
Chapter 5: Electrons in Atoms
5.2 Electron Arrangement in Atoms
• When an electron goes to a higher orbit, its energy .
• When an electron goes to a lower orbit, its energy , and it gives off .
Energy Ladder for H 5 E = 2.09 x 10-18
J4 E = 2.06 x 10-18
J3 E = 1.9 x 10-18 J2 E = 1.6 x 10-18 J
1 E = 0 Joules
If an electron goes from orbit 1 to orbit 3, how must its energy change?
From orbit 3 to 2?
From orbit 2 to 1?
Say goodbye to Bohr’s Model
Types of orbitals: 1) Spherical Orbital
2) Pear shaped orbital
3) Complex shaped
Problems with the Orbit Model 1. Bohr’s model only predicted the line spectrum for one atom, .2. Every orbit is unstable. The orbiting particle always “falls” into the center of the orbit.
A new model was needed…- electrons do not orbit the nucleus - electrons have properties of both and
.Modern Model, Quantum Model Electrons are in orbitals, 3 dimensional regions
around the nucleus that indicates the ____ location of an electron.
Electrons “live in” orbitals.
An orbital is like a room. Shell: The main energy level occupied by the electron. (Principal Quantum Number, n)Subshell: Different shapes of the main energy level. (Angular Momentum Quantum Number, l)
When electrons are put in the orbitals,- the electrons fill low energy “rooms” first, higher energy rooms next.(Aufbau principle)- each “room” can only hold 2 electrons
The Electron Hotel
Third Floor
Second Floor
First FloorOrbital Energy Diagram- See pg 133
Fig 5-7Electron Configuration (Spectroscopic
Notation) H 1s1 He 1s2 O 1s22s22p4
Electron Arrangements
Using the orbital filling diagram on page 133 of your book, write the electron configurations for:
F (9 e-) =
Ni(28 e-) =
Mg(12 e-) =
Orbital (Electron) Energy Diagram 46
4s 3d
3s3p
E 2s2p Phosphorous ( e -)
1s
Electron ConfigurationP (15 e -) =Valence electrons:Noble Gas Notation:
1s22s22p5
1s22s22p63s23p63d84s2
1s22s22p63s2
1s22s22p63s23p3
3s23p3
[Ne]3s23p3
Final Rules• Pauli Exclusion
Principle:• No more than____
electrons are in the same orbital
• Hund’s Rule:
• Orbitals of equal energy are each occupied by one electron before any orbital is combined with a second. (remember negative repels ______)
5.3 Physics and the Quantum Model
Light: Energy that moves through space as a wave.
Properties of waves:Wavelength (l)- The distance from one wave crest to the
next wave crest. Measured in mm, cm, or meters.Frequency (v)- The number of wave crests that pass a
certain point each second. Measured in waves/sec, 1/sec or Hertz
Speed (c)- How fast the wave travels through space. Light travels at a constant speed of 2.998 x 108 m/sec.
You can do the algebra!
Wavelength, Frequency and Speed are related to each other for any wave.
(Wavelength)(Frequency) = Speed of lightor (l) (v) = c λ = c
c= 2.998 x108 m/s v Example: What is the wavelength of a light wave whose
frequency is 5.5 x 10 12 1/sec?
Example: What is the frequency of a light wave whose wavelength is 7.0 x 10 -7 meter?
The Electromagnetic SpectrumThe Electromagnetic spectrum is all of the forms of light,
both visible and invisible to our eyes.
10-16 10-11 10-8 4 x 10-7m 7 x 10-7m 10-3 1 m 103
l Wavelength as you move to the right. Energy as you move to the right.
Gamma Ray
X-Ray Ultra VioletRays
Violet
Blue
Green
Yellow
Orange
Red
Infra red Waves(heat)
Micro waves
Radio and TV Waves
How much energy does light have? • Light moves through space as wave packets
called “photons.” A photon is like a particle of light.
• Light’s energy can be determined by using:E = h v E= Energy v= frequency
where h = Planck’s constant = 6.626 x10 -34 Joule(sec) photon
Example: What is the energy of a photon whose frequency is 5.3 x 10 14 1/sec?
World in Motion: Wave Particle Duality
• 1. How do you prevent cellular damage by the use of x-rays?
• 2. Describe the Compton effect.• 3. Give two equations from the movie and give the
variables meaning.• 4. How do you find the wavelength of a solid object?
Cornell Notes: Bohr Atom Model
Atoms and light.1. What is the difference between
absorption lines and emission spectral lines?
2. If an atom releases light it must first gain something. What?
3. What happens to the electron when the atom gains energy?
4. Does the electron (atom) stay excited forever? What is released to stabilize the atom again?
Bohr Atom
Important points, supporting details.
Write a two sentence summary about what you have learned.
Periodic Table: Properties of Elements
• DVD questions:1. What does an element’s location on the “PT” tell you about?2. Why are the elements on the end called Noble gases?3. Going right across the PT, what happens to the charge?4. What factors affect the size of an atom’s valence shell?5. Low ionization energy leads to the loss of what?6. Give the common trait of metals.
Noble Gas Shorthand Activity-