Ch. 11 Notes---Electrons in Atoms Atomic Models (See Fig. 13.2) (1) Model: a ball of (+) charge...
-
Upload
jonah-parsons -
Category
Documents
-
view
216 -
download
0
Transcript of Ch. 11 Notes---Electrons in Atoms Atomic Models (See Fig. 13.2) (1) Model: a ball of (+) charge...
Ch. 11 Notes---Electrons in AtomsAtomic Models(See Fig. 13.2)
(1) Model:
• a ball of (+) charge containing a number of e-
• no ________________
• often described as the “________ _______________” atom.
(2) Model:
• a ____________ of (+) charge surrounded by a number of e-
• no _____________ and no e- orbitals
Thomson
nucleus
plum pudding
Ch. 13 Notes---Electrons in AtomsAtomic Models(See Fig. 13.2)
(1) Model:
• a ball of (+) charge containing a number of e-
• no ________________
• often described as the “________ _______________” atom.
(2) Model:
• a ____________ of (+) charge surrounded by a number of e-
• no _____________ and no e- orbitals
Thomson
nucleus
plum pudding
Rutherford
nucleus
neutrons
(3) Model:
• a nucleus of (+) charge that also contains ______________
• nucleus is encircled by e-’s located in definite orbits (or paths).
• e-’s have ___________ energies in these orbits
• e-’s do not lose energy as they orbit the nucleus
(4) Mechanical Model:
• no definite ____________ to the e- path (“fuzzy” cloud)
• orbits of e-’s based on the _________________ of finding the e- in the particular orbital shape.
Atomic Models
Bohr
neutrons
fixed
Let us have a moment of silence
(3) Model:
• a nucleus of (+) charge that also contains ______________
• nucleus is encircled by e-’s located in definite orbits (or paths).
• e-’s have ___________ energies in these orbits
• e-’s do not lose energy as they orbit the nucleus
(4) Mechanical Model:
• no definite ____________ to the e- path (“fuzzy” cloud)
• orbits of e-’s based on the _________________ of finding the e- in the particular orbital shape.
Atomic Models
Bohr
neutrons
fixed
Quantum
shape
probability
Schroedinger's Cat
Quantum Mechanical
Model
Diagram: (Fig. 13.3)
• The energy levels in an atom are sort of like _________ of a ladder.
• The more energy an electron has, the __________ away from the nucleus it usually will be.
• The energy levels are not evenly spaced. They get ___________ together as you travel farther away.
• To move from one “rung” to another requires a “____________” of energy.
Energy Levels
rungs
farther
closer
quantum
continuous energy levels quantized energy levels
Quantum Numbers
• Describe the ______________ of the e-’s around the nucleus.
• Quantum #’s are sort of like a home _____________ for the electron.
• This information about the location of the e-’s in an atom can be used to:
(1) determine chemical & physical _____________ for the elements.
(2) show how the _______________ __________ is organized.
(3) show _____ and _____ elements combine to form compounds.
location
address
properties
Periodic Table
how why
The Four Quantum Numbers• Principal Q. #: Describes the _____________ that the
electron is from the nucleus. The bigger the number, the ___________ away the electron is.
Example: (1=closest, 2, 3, 4...farther away) These distances are sometimes called _____________________________ ____________.
12
3 nucleus
distance
farther
principal energy levels
• Orbital Q. #: Describes the __________ of the electron’s path around the nucleus with a letter: (s, p, d, & f) These are sometimes called “_____________”.
s=_____________ cloud; p=_____________ or a 3-D figure 8;
shape
sublevels
spherical ellipsoid
• d & f orbital shapes are complex ________- _______________ ellipsoids, and some d’s and f’s are an ellipsoid with a doughnut or two around the middle.
• All of these orbital shapes are based on the probability of finding the electron in the cloud. (See p. 365)
d - orbitals
f - orbitals
crisscrossing
• Magnetic Q. #: tells how many _________________ in 3-D there are about the nucleus for each orbital shape.
s=___ orientation p= ___ orientations... (x, y, and z)
d= ___ orientations f= ___ orientations
• Spin Q. #: describes how the electron in an orientation is spinning around the nucleus. This spin can be thought of as “____” or “________”. (Some like to imagine it spinning “clockwise” and “counterclockwise”.) The spin is represented as an ___________ in the direction of the spin.
orientations
1 3
5 7
updown
arrow
• For our class this means that in each orientation there can be up to two electrons.
s=___ electrons p= ___ electrons
d= ___ electrons f= ___ electrons
• Remember, the four quantum numbers tell us the location, or “address” of each electron in an atom.
• This information is vital in understanding the layout of the Periodic Table and the reasoning behind why and how atoms form bonds.
2 6
10 14
Electron Configurations
(Energy Level Diagrams)
1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p…
↑↓
↑
↓
↓
↓
↑
↑
↑
↑
↑↑ ↓ ↓
How Electron Configurations Relate to the Organization of the Periodic Table
sp
d
f
Electron Configurations & Properties• How do electron configurations relate to the chemical and physical
properties of an element?
• All elements with the _________ outer shell e- configurations have the ________ properties.
• This means that elements in the same ____________ group have similar properties.
Examples: (1) Li, Na, K, Rb, and Cs all have __ lone “__” e- for their last orbital... (_____, _____, _____, etc.) This makes all of them ___________ reactive. They all react with __________ to produce hydrogen gas.
(2) Ne, Ar, Kr, Xe, and Rn all have the outer energy level completely __________ with electrons...(________, ________, ________, etc.) This makes all of them ______________. They do not produce __________________!
samesimilar
vertical
1 s1s1 2s1 3s1
very water
filled 2s2 2p6 3s2 3p6
4s2 4p6 inertcompounds
More Practice Problems
(1) Which element has its last electron as a 4p5? ___________
(2) Which elements are similar in properties as Bromine? __________
(3) What would the last outer shell electron configuration be for the element underneath Radon, (Rn)?
(6) What is the shape of the last orbital filled in Calcium, (Ca)? _____
(7) How many electrons are in the last “p-orbital” of Sulfur, (S)? ____
Bromine
F, Cl, I, At
7p6
sphere
4
Electromagnetic Radiation• Any wave of energy traveling at a speed of ___________ is called
electromagnetic radiation.
• There are many types of electromagnetic radiation and each type has a different _______________ and _______________.
• Here are the types of electromagnetic radiation from longest to shortest wave or lowest to highest frequency. These are also in order from lowest to highest energy. (See Fig. 13.10)
light
frequency wavelength
Electromagnetic Radiation
Electromagnetic Radiation(1) Radio Waves -- used in __________________
(2) Microwaves-- broadcasts TV signals and used to _____ _______.
(3) Infrared (IR) -- we feel this as _____; _________ & ______ can “see” this.
infrared image of a cat
infrared image of heating pipes under a floor
heat
cook food
communications
Snakes owls
Infrared
Vision
IR Mr. TTaken at NASA Goddard Space Center in Maryland
Electromagnetic Radiation(4) Visible Light -- the only radiation we can detect with our eyes. It
can be separated into the colors of the spectrum with a __________.
ROYGBIV(5) Ultraviolet (UV) -- gives you a _____________; _________ can
“see” this; some of this radiation from the sun gets blocked by the ___________ layer
flower photo under normal light flower photo under UV light
prism
sunburn Bees
ozone
Electromagnetic Radiation
(6) X-rays -- used in medicine
Ouch!
Electromagnetic Radiation
(6) X-rays -- used in medicine
Macy Slade’s shoulder injury CT scan. OH SNAP.
Electromagnetic Radiation
(7) Gamma Rays-- some radioactive substances give it off
• The last type of radiation is sometimes grouped with gamma rays…
(8)_______________Rays – not trueenergy radiation; almost all of this radiation from the sun is blocked by the ozone layer and our magnetic
field. Consists of charged particles like protons and electrons.
Interesting superhero facts:
• Superman has x-ray vision.
• The Incredible Hulk was “created” by an accidental overdose of gamma radiation.
• The Fantastic Four were “created” by cosmic rays.
Cosmic
How Light is Produced
• When atoms get hit with energy (by _____________ them with electricity or by ____________ them up), the electrons absorb this energy and __________ to a higher energy level. Figure (a)
• As they immediately fall back down to the “____________ state”, they give off this energy in the form of a particle of ___________ (or other types of electromagnetic radiation) called a _____________. Figure (b)
zapping
heating
jump
ground
light
photon
How Light is Produced
• Each photon emitted has a specific ___________ (or frequency).
• The color of the light that is given off depends on how _____ the electron _______ (which depends on how big of a jump it originally made.) The farther the fall, the ___________ energy the photon has.
color
far fell
greater
How Light is Produced• Since electrons are located only in certain __________ levels (or
orbitals) around the nucleus, only certain specific _________ of light are emitted.
• Scientists use a _________________ to separate these colors into bands of light. These bands of color look like a ______ code of color which is characteristic of that element. No two elements produce the same ______________ of colors. This can be used to distinguish one element from another contained in a sample. (See Fig. 13.11)
energy
color
spectroscopebar
spectrum
Emission Spectrum
Hydrogen Spectrum
Neon Spectrum
How hydrogen produces the four visible photons