Electrons Chapter 5

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Problem Set
2b

Chemistry




Electrons



C
hapter 5

Due
Wedne
sday

October 1
3
th





Test
Friday

Oct
1
5
th








Atoms, Radioactivity and Electrons



All your work is to be done on separate sheets of paper.



S
taple

your work

together with this question sheet at the
back

of the packet.



Each of your responses
should
be numbered as it appears on the question sheet.



All your work must be shown in your own handwriting.



Check your answers for the practice questions with the an
swers I provide.



Pen or pencil is acceptable. Please no red pens, we’ll use those to score in class.



Work together… but don’t copy each other. Copied work will
not help you learn.



You should plan on completing between 4 and 8 questions a night for homewor
k.


Light and Quantized Energy

Conceptual Questions

1)

Draw a wave and label the following: wavelength, node, amplitude, crest, trough.


2)

Use a ruler to d
raw two waves:
Wave A

should have a wavelength of 5
.00

centimeters and
Wave B

should have a wavelength of 3
.00

centimeters.
Assuming both are traveling at the speed of light (3.00 x 10
8
m/s), which one have
a higher frequency? Which one has a higher energy?


3)

What are
three characteristics that scientists use to
describe
the behavi
or of
electromagnetic
radiation as
waves?


4)

What is the formula that relates frequency, wavelength and speed? How are
frequency and wavelength related?


5)

Mr. Williamson’s favorite radio station is WVPR 107.9 MHz. However, he
listens to the Red Sox on 550 k
Hz on the AM dial.

a.

What is the energy of each radio stations?

b.

What is the wavelength of each radio stations?

c.

Should Mr. Williamson worry about listening to the radio and the
electromagnetic radiation it picks up?


6)

What is an atomic emission spectrum?

Can every color of light be seen in an
atomic emission spectrum of an element? Can every color of light be seen in the
emission spectrum of the sun?


Practice Questions

7)

Place the following types of radiation in order from the lowest energy to the
highes
t energy: microwaves, ultraviolet,

-

rays

(gamma), radio waves, red light
and x
-
rays.


8)

What is the unit used to measure frequency?


9)

Most CD players use a wavelength of light that is 780nm. What is the frequency
of this light? What is its energy? Where

does this type of wave fall on the
electromagnetic spectrum?

10)

What color is a light wave if its wavelength is 700 nm?


11)

If an electromagnetic wave has a wavelength of 530 nm what is its frequency? It’s
energy?

What type of electromagnetic radiation is it?


12)

If an electromagnetic wave has a frequency of 6.00 x 10
14
Hz, what is its energy?
It wavelength?

What type of electromagnetic radiation is it?


13)

If an electromagnetic wave has 9.49 x 10
-
20

J
oules of energy
, what is its
frequency? Its wavelength? What type
of electromagnetic radiation is it?


Extension

Question

14)

Answer question 71 from page 147 in your text.


Quantum Theory and the Atom

Conceptual Questions


15)

What is the difference between a
n atom’s

ground state and
its

excited state
?


16)

What is the limitation
with Bohr’s calculations and atomic model?


17)

What does this expression help define: 2n+2 ?


Quantum Theory and the Atom

Practice
Questions


18)

How many sublevels are there in the


a.

First

Energy Level?

b.

Second
Energy Level?

c.

Third
Energy Level?

d.

Fourth

Energy Leve
l?



19)

Which of the following orbital
s

DO NOT exist? (there is more than one)

a.

4s

b. 3d


c. 2f


d. 1p


e. 5f


Electron Configurations

(5.3)

Conceptual Questions


20)

What is the aufbau principle? Where did that word “aufbau” come from?


21)

What is the Pauli
exclusion principle? What does it
ensure for each electron?


22)

What is Hund’s Rule? Why doesn’t it apply to any element smaller than carbon?


23)

How does noble gas notation shorten an electron configuration?


24)

Write the electron configuration for Ca, Ca
+1
, Ca
+
2

and Ar.


25)

Describe how the orbital diagrams in the previous question compare. Which of
them are
isoelectronic
?


26)

Define the term
Valence Electron

and describe how that relates to how electrons
are important in co
valent

bonding.


Electron Configurations
(5.3)

Practice

Questions


27)

Identify the
atomic numbers

and the name of the elements with the following
electron configurations:

a.

1s
2
2s
2
2p
2

b. 1s
2
2s
2
2p
6
3s
2
3p
1

c. 1s
2
2s
2
2p
6
3s
2
3p
6
4s
2
3d
10
4p
6
5s
1
4d
10



28)

Write the electron configuration for the following

a.

magnesium

b. iron


c. sulfur

d. aluminum


29)

Identify the element represented by each of the following orbital diagrams.


a






_



1s 2s


b
















.


1s 2s 2p


c.




















.


1s 2s 2p 3s


d.




























.



1s 2s 2p 3s 3p



30)

Use the short cut, noble gas configuration, to write the electron configuration for
th
e following elements:

a.

Sr


b. Rb


c. Ge


d. Br


e. V


31)

Identify the following atoms by their condensed electron configurations:

a.

[He]2s
2
2p
1


c. [Ne]3s
2


e. [Ar] 3d
10
4s
2
4p
5

b.

[Ne]3s
2
3p
1


d. [He]2s
2


f. [Kr] 4d
10
5s
2
5p
5


32)

Draw the electron dot diagram for the
following elements:

a.

Sodium


d. fluorine


g. neon

b.

Lithium


e. chlorine


h. argon

c.

Potassium


f. bromine


i. xenon


33)

Answer the 10 multiple choice questions at the end of the chapter on page 149.



Electron Configurations (5.3)

Practice

Questions


34)

Look at pra
ctice question #31: What are the similarities between

“a” and “b”?

and “c” and “d”? and


“e” and “f”?


35)

Look at your drawing for practice question32. Is there a trend in the groups of
elements a, b, and c? What about the group d, e, and f? and g, h, a
nd i?


36)

There are 20 total electrons in an atom of calcium.

a.

How many of them are valence electrons?

b.

What charge do all electrons have?

c.

What are the 18 non
-
valence electrons doing to the two valence electrons?

d.

What are the 20 protons in a calcium nucle
us doing to all the electrons in
the atom?

e.

Which electrons are feeling the attraction the most?

f.

Which electrons feel the attraction the least?


37)

There are 19 electrons in an atom of potassium.

a.

How many filled orbitals are there in the atom?

b.

How many filled sub
-
levels?

c.

How many energy levels are filled?

d.

Which orbital(s) is/are only partially filled?


38)

There are 33 electrons in an atom of arsenic.

a.

How many filled orbitals are there in the atom?

b.

How many filled sub
-
levels?

c.

How many energy

levels are filled?

d.

Which orbital(s) is/are only partially filled?


39)

A zinc atom has a total of 30 electrons. 18 of them are found in the 3s, 3p and 3d
orbitals. Why is its electron dot diagram
Zn
:
?


Big Picture

Questions

40)

Why are electrons the most impo
rtant part of an atom?


41)

Define the term quantum. Use it in a sentence and give an everyday example of a
quantized amount of something you might buy.


42)

How does an orbit differ from an orbital?


43)

What is an electron configuration? Why do chemists use them?


44)

What is an orbital diagram? How are they different from electron configurations?


45)

Why are Valence electrons SO important in chemistry?


Answers to Practice Questions

7)

Lowest energy to the highest energy:

Radio waves < microwaves < red light < ultraviolet
< x
-
rays <

-

r慹猠


8)

What is the unit used to measure frequency?

Hertz


9)

Most CD players use a wavelength of light that is 780nm.


a.

What is the frequency of this light?

c =




3 x 10
8

m/s = 7.8 x 10
-
7
m




3.85 x 10
14

Hz

b.

What is its energy?

E
= h



E = 6.62 x 10
-
34

J/Hz (3.85 x 10
14

Hz)


E‽′⸵㔠砠
10
-
19
J

c.

Where does this type of wave fall on the electromagnetic spectrum?
These are all descriptions of
infrared

light wavelengths.


10)

What color is a light wave if its wavelength is 700 nm?

Red


11)

If

an electromagnetic wave has a wavelength of 530 nm



a.

W
hat is its frequency?

3.00x 10
8

m/s = 5.30 x10
-
7
m (






= 5.66 x 10
14

Hz

b.

It’s energy?


E = h




E‽
㘮㘳⁸‱
-
34
Js)(5.66x10
14
Hz) = 3.75 x 10
-
19
J

c.

What type of electromagnetic radiation is it?

Visible light (a shade of purple)


12)

If an electromagnetic wave has a frequency of 6.00 x 10
14
Hz…

a.

W
hat is its energy?

E = h




E‽
㘮㘳⁸‱
-
34
Js)(6.00x10
14
Hz) = 3.98 x 10
-
19
J


b.

It wavelength?


c =




㌮〰砠㄰
8

m/s = (

⠶⸰(砱
14
Hz

)




= 5.00 x10
-
7

m

c.

What type of electromagnetic radiation is it?

Visible light


bluish green


13)

If an electromagnetic wave has 9.49 x 10
-
20
J
oules of energy


a.

W
hat is its frequency?

E = h




㤮㐹砱9
-
20
J = (6.63 x 10
-
34
Js)(

⤠㴠ㄮ㐳⁸‱
14
Hz

b.

Its wavelength?

c =




㌮〰砠㄰
8

m/s = (

⠱⸴(砱
14
Hz

)


2.09 x 10
-
6
m

c.

What type of electromagnetic radiation is it?

Infrared energy (heat)


18)

How many sublevels are there in the …

a.

1
st

Energy Level?
1 (s)


b. 2
nd

Energy Level
? (2

s, p)

c. Third Energy Level?

(3 s, p, d)

d. 4
th

Energy Level?
(4
-

s, p, d, f)


19)

Which of the following orbital
s

DO NOT exist? (there is more than one)

a.

4s


b. 3d


c. 2f


d. 1p


e. 5f

The 2
nd

energy

level has 2 sublevels in it (s and p), so there can be no orbital
higher than an p.

The first energy level has only one sublevel in it, so there can be no orbital
higher than an s.

27)

Identify the
atomic numbers

and the name of the elements with the followin
g
electron configurations:

a. 1s
2
2s
2
2p
2

b. 1s
2
2s
2
2p
6
3s
2
3p
1

c. 1s
2
2s
2
2p
6
3s
2
3p
6
4s
2
3d
10
4p
6
5s
1
4d
10


6

= carbon


13 = aluminum


47 = silver

28)

Write the electron configuration for the following

a.

magnesium


b. iron



1s
2
2s
2
2p
6
3s
2


1s
2
2s
2
2p
6
3s
2
3p
6
4s
2
3d
6

c. sulfur


d. aluminum

1s
2
2s
2
2p
6
3s
2
3p
6

1s
2
2s
2
2p
6
3s
2
3p
1


29)

Identify the element represented by each of the following orbital diagrams.


a

lithium






_



1s 2s


b

oxygen
















.


1s 2s

2p

c.

sodium



















.


1s 2s 2p 3s


d. chlorine



























.




1s 2s 2p 3s 3p


30)

Use the short cut, noble
gas configuration, to write the electron configuration
for the following elements:

a.

Sr

[Kr]5s
2


b. Rb

[Kr]5s
1


c. Ge
[Kr] 5s
2
4d
10
5p
2



d. Br
[Kr] 5s
2
4d
10
5p
5



e. V
[Kr] 5s
2
4d
3


31)

Identify the following atoms by their condensed electron configurations:

a.

[He]2s
2
2p
1

B


c. [Ne]3s
2

Mg


e. [Ar] 3d
10
4s
2
4p
5

Br

b.

[Ne]3s
2
3p
1

Al


d. [He]2s
2

Be


f. [Kr] 4d
10
5s
2
5p
5


I


32)

Draw the electron dot diagram for the following elements:







a.

Sodium
Na
.


d. fluorine
:F:


g. neon
:Ne:


b.

Lithium
Li
.


e. chlorine
:Cl:

h. argon
:Ar:


c.

Potassium
K
.


f. bromine
:Br:


i. xenon
:Xe:



33)

1:


2:

3:

4:

5:

6:

7:

8:

9:

10:

..



..

.



..

..



..

.



..

..



..

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