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Unit 2 Note Companion
Atomic Structure
Subatomic Particle in the Atom
Particle
Location
Charge Mass
Proton
Neutron
Electron
Atomic Symbol
Draw and Label the atomic symbol for Gold
Examples
• Write the atomic Symbol for Silver
•
Write the atomic symbol for carbon
•
Write the atomic symbol for Carbon-12
Atomic number and mass
Atomic number =
Atomic mass=
What is an isotope?
What is an ion?
Examples
Element
Protons
Neutrons Electrons
Carbon-13
Ca 2+
F131
53
I
131
54
Xe
Summary
Average Atomic Mass
What is average atomic mass?
• _______________ average of all isotopes (like your grades)
• on the Periodic Table
• round to 2 decimal places
Average atomic mass=
•
Calculate the avg. atomic mass of oxygen if its abundance in nature is 99.76% 16O,
0.04% 17O, and 0.20% 18O.
Summary
History of the Atom-Part 1
Democritus
• The first ___________________________
• Matter is made of empty space through which _________________________
• Atoms are ___________________________________________
• _______________atoms have _______________sizes and shapes
• Changes in matter are due to changes in _____________________________________________
What is the law of conservation of matter?
Matter cannot be
Law of Definite Composition
A compound will have the ___________________________________________________
Will always have the same ratio
Dalton’s Atomic Theory
• All matter is made of small, _____________________________________called atoms
• Atoms of the__________ element have ________________________________
• Atoms of __________________ elements have ____________________________
• Atoms obey the _________________________________________
Atoms obey the _________________________________________
Law of Multiple Proportions
If two elements can make
Summary
History of the atom- Part 2
Briefly Explain the Cathode ray Experiment that Thomson performed
Plum Pudding Model
• When Thomson ________________________________________, he came up with a model for
the structure of the atom
• Atoms are ____________________________________
_____________________________________________
• No “anode rays”, so it was thought that the _______________________________________
were seen as ___________________________________ from one place to another
Briefly Explain the Gold Foil Experiment that Rutherford performed
Explanations to Rutherford’s Observations
Positively charged alpha particles would pass through most of the time without being
deflected
Some particles were deflected
Nuclear model
The positive charge is all concentrated in the
Summary
The Bohr Model
Bohr Model
e- (electrons) only exist in orbits
Therefore
Bohr Model
• Concluded the electrons _____________________________________________
• The orbitals ________________to the nucleus have the _______________ amount of energy
and the orbitals gain energy the _______________ they get from the nucleus
How the Bohr model relates to light
• When an atom is at rest, each electron lies in its
_____________________________________________
• Energy is __________________to an atom, the electrons ____________ it and jump to
_________________________ orbitals (_______________________)
•
•
•
The electrons fall back to the _________________________, giving off the energy as
______________
Because there are so many orbitals, there are only ___________________________ of light
that can be given off by an atom
No two atomic spectra will ever be the same (the light given off by the atom)
What is spectroscopy?
Problems with Bohr model
Even though
It only worked for
Summary
The Modern Atom
Light is a Wave
Light is characterized by
Draw and label the diagram of the wave
Wavelength (λ)=
Frequency (v)=
How are wavelength and frequency related?
Frequency and wavelength are inversely proportional, which
means_____________________________________
Equation for the speed of light
•
•
•
c:
:
:
speed of light (3.00  108 m/s)
wavelength (m, nm, etc.)
frequency (Hz)
Find the frequency of a light particle with a wavelength of 434 nm.
How Are Frequency and Energy Related?
The energy of a wave is proportional to its frequency, which means
__________________________________________
Equation for energy
E:
h:
:
energy (J, joules)
Planck’s constant (6.6262  10-34 J·s)
frequency (Hz)
Find the energy of a red photon with a frequency of
4.57  1014 Hz.
The Electromagnetic Spectrum
__low_Wavelength
________Frequency
____high__Energy
___________Wavelength
____low_frequency
__________energy
Gamma Rays, Xrays, UV, Visible, Infrared, Microwaves, Radiowaves
Light is quantized
When something is quantized, it means
Planck concluded
Light is a particle
Einstein concluded
Einstein observed a certain frequency
Defined a light particle as a _______________
Summary
The Quantum Model- Standard
Modifications of the Bohr Model
• In the Bohr Model there was only one variable on where the electrons were
(___________________________________________________________________________)
• Schrodinger proved there were 4 variables on where the electrons were
• 4 quantum numbers
This idea is similar to the idea of an address
• 1st Quantum number or the Principle Quantum number
• This number determine the main _________________________________
• Also indicates the ______________ of the orbital
•
•
2nd Quantum Number or the Angular Momentum Quantum Number
Determined the _________________________ of the electron (_________________ of the
orbital)
•
•
•
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3rd Quantum Number or the Magnetic Quantum Number
Determines the ___________________________ of the orbitals
Can be oriented in three ______________________
This number tells you what _______________ the electron is in
•
•
The 4th quantum number or the Spin Quantum Number
This number indicates which electron we are talking about in the orbital (each
orbital can hold two electrons)
• An orbital can hold _________electrons that spin ___________________________
directions.
•
Pauli Exclusion Principle
• No two electrons in an atom can have the same 4 quantum numbers.
• Each e- has a unique “address”:
Principal #Ang Mom #Magnetic #Spin #Summary