Expected Test Date Thursday Feb 5 th -6 th AP Chemistry Chapter 7 Atomic Structure and Periodicity 1
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- Expected Test Date Thursday Feb 5 th -6 th AP Chemistry Chapter
7 Atomic Structure and Periodicity 1
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- What is Atomic Structure and Periodicity? Evidence of the
atomic structure How groups and periods show similar properties
Most of this has to do with the arrangement of atoms in an element
2
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- Chapter 7.1 Electromagnetic Radiation Electromagnetic
Radiation: Energy that travels through space at the speed of light;
examples Light from sun, energy for microwave, X Rays These seem
different but they all travel in waves and have specific
wavelengths Wavelengths: Distance between two consecutive peaks
between wavelengths Symbol 3
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- Chapter 7.1 Electromagnetic Radiation Frequency: Number of
wavelengths per second Symbol v EQUATION TO REMEMBER c = v Given to
you on ap exam formula sheet c = speed of light which is 2.998X10ms
-1 Speed of light also given to you on AP Chemistry formula sheet
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- Chapter 7.1 Electromagnetic Radiation 5
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- SA Question 1 on Chapter 7 AP Chem Exam. Book Sample Exercise
7.1 6
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- Solution 7
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- 7.2 Nature of Matter All matter emits an electromagnetic
radiation. At first this made scientists think that matter and
energy are the same things however in the early 20 th century Max
Planck showed again that energy and matter are the same thing
Planck determined that energy can be gained or lost only in whole
number multiplies of hv where h is plancks constant 8
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- 7.2 Nature of Matter Equation to know for nature of matter E =
nhv E is energy, n is an integer, h is Plancks constant (6.626X10
-34 Js), and v is frequency 9
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- SA Question 2 on Chapter 7 AP Chem Exam. Book Sample Exercise
7.2 10
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- Solution 11
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- 7.11 The Aufbau Principal and the Periodic Table Electron
configuration 12
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- 7.11 The Aufbau Principal and the Periodic Table What is the
electron configuration of stromium? Draw a picture of how electrons
move around the nucleus. 13
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- 7.11 The Aufbau Principal and the Periodic Table 14
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- 7.11 The Aufbau Principal and the Periodic Table 15
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- 7.11 The Aufbau Principal and the Periodic Table 16
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- 7.11 The Aufbau Principal and the Periodic Table 17
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- 7.11 The Aufbau Principal and the Periodic Table Aufbau
Principle: As protons are added one by one to the nucleus to build
up the elements, electrons are similar added to these hydrogenlike
orbital's. Hunds rule: the lowest energy configuration for an atom
is the one having the maximum number of unpaired electrons. 18
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- 7.11 The Aufbau Principal and the Periodic Table 19
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- 7.11 The Aufbau Principal and the Periodic Table 20
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- 7.11 The Aufbau Principal and the Periodic Table Write the long
hand and short hand electron configurations for the following
elements Chlorine Argon Potassium 21
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- SA Question 3 on Chapter 7 Test Know where the s, d, p, and f
block elements are and the numbers associated with them. Hence be
able to label the periodic table in last slide. Be able to identify
an element based on the configuration number i.e. 4s 2 = Calcium
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- SA Question 4 on Chapter 7 Test, sample question 7.7 25
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- Solution 26
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- Solution 27
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- 7.12 Periodic Trends Valance electrons = Roman number = s + p
number All atoms are unstable until they have 8 valence electrons
(same as noble gasses) 1. Answer these questions about the atoms.
a. What is the s or the s + p orbitals for the following? b. How
many valance electrons does it have? Li = Ne = I = 28
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- 7.12 - Atomic Radius Atomic radius is approximately the
distance from the nucleus of an atom to the outside of the electron
cloud where the valence electrons are found. The reactivity of the
atom depends on how easily the valence electrons can be removed,
and that depends on their distance from the attractive force of
nucleus. Since protons and electrons are attracted to each other
the size of the radius changes based on how many protons there are.
Also whenever an s orbital is added the atomic radius increases.
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- 7.12 Atomic Radius Think of it like this: Across a period,
protons increase. Down a group, s orbitals increase So as you move
from left to right across a period, the atomic size? __________
Why? So as you move down a group the atomic size? _________ Why?
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- 7.12 Ionization energy Ionization energy is the energy needed
to overcome the attraction between the positive charge of the
nucleus and the negative charges of the electrons and remove
electrons from an atom. Think of ionization energy as how strongly
an atoms nucleus holds onto its valence electrons(outermost
electrons). A high ionization energy value indicates that an atom
has a strong hold on its valence electrons and is less likely to
lose its electrons. A low ionization energy indicates that an atom
has a weak hold on its valence electrons and is likely to lose one
or more electrons. 31
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- 7.12 Ionization energy Think of it like this: If an atoms want
to lose an electron it has a low ionization energy. Also if this
electrons are far away from protons, it is easier to lose it. So as
you move from left to right across a period, the ionization energy?
__________ Why? So as you move down a group the ionization energy?
_________ Why? 32
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- 7.12 Electronegativity The electronegativity of an element
indicates the relative ability of its atoms to attract electrons in
a chemical bond. Keep in mind all atoms want 8 total valance
electrons. These values are calculated on a number of factors and
are expressed in terms of a numerical value of 4.0 or less. The
units used to express electronegativities are called Paulings.
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- 7.12 Electronegativity Think of it like this: Atoms that want
electrons will have a higher electronegativity So as you move from
left to right across a period, the electronegativity? __________
Why? So as you move down a group the electronegativity? _________
Why? 34
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- 7.12 Electron Affinity The electron affinity of an element is
the energy given off when a neutral atom in the gas phase gains an
extra electron to form a negatively charged ion. A fluorine atom in
the gas phase, for example, gives off energy when it gains an
electron to form a fluoride ion. 35
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- 7.12 Electron Affinity Think of it like this: An atom wants to
lose an electron then it will release more energy. So as you move
from left to right across a period, the electronegativity?
__________ Why? So as you move down a group the electronegativity
energy? _________ Why? 36