Download Isotopes Lecture

Unit 2 Atomic Structure - Isotopes
Agenda
• Basic Atomic Structure
Review
• Phet Computer Activity
• Reading a Periodic Table
Tile
• Practice Determining# of
Subatomic Particles
Monday
Tuesday
Wednesday
Thursday
Friday
Atoms: the building blocks of matter?
Never trust an
Atom! They
make up
everything!
Image via ThinkGeeks
An atom is the smallest unit of an
element that is possible.
All the matter around us
is made of individual
atoms. Sometimes different
atoms join together to
form new substances.
O
H
H
Molecule: consists of individual
atoms in fixed proportions.
Two Hydrogen Atoms will
join an Oxygen atom and
form water (H2O).
In this sense atoms are the building blocks of matter but
atoms are usually made up of three smaller particles and two
of those particles are made up of even smaller particles. So
an atom is not a fundamental building block of matter.
The Atom
An atom consists of a
• Nucleus (protons and neutrons)
• Electrons in space about the
nucleus.
Electron cloud
Nucleus
Protons, Neutrons and Electrons
• Positively charged (+1).
• Found in the nucleus.
• Defines what an atom is.
• Neutral particle in an atom.
• Found in the nucleus.
• Required for stability.
• Negatively charged particle (-1).
• Found outside the nucleus.
• Main cause of Chemical Bonding.
The ATOM
The atom is
mostly empty
space
Most of the mass of an atom
is in the nucleus.
Protons, Neutrons and Electrons
• Protons and Neutrons are roughly equal in mass but a
neutron is ever so slightly bigger than a proton.
• Therefore we say that each has a mass of 1 amu (atomic
mass unit)
Protons, Neutrons and Electrons
• Protons and Neutrons are roughly equal in mass but a
neutron is ever so slightly bigger than a proton.
• A proton (and a neutron) are about 1800 times as massive
as an electron.
The mass of a proton
and electron would
NEVER balance!
Protons, Neutrons and Electrons
• Protons and Neutrons are roughly equal in mass but a
neutron is ever so slightly bigger than a proton.
• A proton (and a neutron) are about 1800 times as massive
as an electron.
Protons, Neutrons and Electrons
• Protons and Neutrons are roughly equal in mass but a
neutron is ever so slightly bigger than a proton.
• A proton (and a neutron) are about 1800 times as massive
as an electron.
It would take 1800 Electrons to
balance with 1 Proton or Neutron!
Electrons
Travel around the
nucleus in
the electron cloud
which is mostly empty
space
• In a neutral atom the number of
electrons is equal to the number of
protons since that is the only way to
have a “net” charge of zero.
Remember!!!!
Protons have a
charge of +1
Electrons have
a charge of -1
Neutrons have NO charge
WHAT AFFECT DOES CHANGING
THE NUMBER OF SUBATOMIC
PARTICLES HAVE ON AN ATOM?
Phet Simulation: Build an
Atom
1. Log into your
chromebook and
google search the
words “Phet” and
“build an atom”
2. Follow the
directions in your
guided notes and
answer the
questions
3. You have 10 mins to
complete this!!!
Phet Simulation: Build an
Atom
1. What particle
determines what
element you have?
2. What particle(s)
can change without
changing the
identity of an
element?
Key Vocabulary
• Isotope – atoms of the
same element that have
the same number of
protons but a different
number of neutrons
• Ions –
atoms of
the same
element
that have
the same
number of
protons
but
different
number of
electrons
What is an Isotope?
• Isotopes are atoms of the same element that have
the same number of protons but a different number
of neutrons.
• All elements consist of naturally occurring isotopes
and artificially produced isotopes
How are isotopes of an element similar? How
are they different?
The isotopes of an element have:
• Identical Chemical Properties (this is because they have the
same numbers of protons and electrons and subatomic
particles are responsible for chemical behavior)
• Different Physical Properties (different mass and different
number of neutrons)
What do you need to be able to do
with Isotopes
1. Use the isotope symbol to determine the
number of subatomic particles present in AN
ATOM of the isotope
Two stable isotopes of carbon are
carbon-12 and carbon-13.
12
6
13
6
C
C
Protons_________
Neutrons________
Electrons ________
#p + #n
)
X
A
Z
(in neutral atom)
#p
symbol
Protons_________
Neutrons________
Electrons________
(in neutral atom)
We can express the isotopes of carbon using subscripts and superscripts
Image via pearson Chemistry textbook
20
10
Ne
21
10
Ne Ne
21
10
Recall - What you need to be able to
do with Isotopes
1. Use the isotope symbol to determine the
number of subatomic particles present in AN
ATOM of the isotope
2. Use the periodic table to determine the
number of subatomic particles present in an
atom of the MOST NATURALLY ABUNDANT
isotope for that element
1
H
There are three types of hydrogen but the vast majority
of hydrogen is protium.
The atomic mass is a weighted average of all the types
of hydrogen.
Hydrogen
1.00794
So if you had a bag filled with hydrogen gas, it would
have all three types but most of it would be protium.
Therefore, we round the average atomic mass to the
nearest whole number
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
HH
H
H
H
H
H
H
H H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
How to Read a Periodic Table Tile
Atomic Number (Z)
# of protons
11
Element Symbol
2
8
1
Number of
electrons in each
Primary Energy
Level
Na
Sodium
22.9897
Element Name
Average Atomic
Mass
6
A neutral carbon atom has
how many of each particle?
C
Protons:_______
CARBON
Neutrons:______
12.01
Electrons:_____
The 6 on the top is the atomic number of carbon and that is
also the number of protons any atom of carbon must have.
The 12.01 on the bottom is the average atomic mass and is
also the number of protons and neutrons in average carbon
atom. Six of those 12 must be protons because Carbon has an
atomic number of 6 so what is left over are neutrons.
An electrically neutral atom must have an overall charge of
0. This means the total number of electrons (-1 charge) must
be equal to the number of protons (+1 charge).
Proton Number = Atomic Number.
Neutron Number:
Atomic Mass (rounded) minus Atomic
Number.
(or bottom minus top)
Electron Number = Proton Number (if Neutral)
10
Ne
NEON
20.18
Protons:_______
Neutrons:______
Electrons:_____
8
Protons:_______
O
Neutrons:______
Oxygen
Electrons:_____
15.99
+1
+1
+1
+1
+1
+1
+1
+1
0
0
0
0
0
0
0
0
-1
-1
-1
-1
-1
-1
-1
-1
Why do we only consider the
number of neutrons and
protons when determining
the mass number of an
atom?
CONCEPT CHECK
ANSWER: Electrons are much lighter
than protons and neutrons so we
can ignore them.
Practice 1
Element
Name
Element
Symbol
Atomic
Number
Atomic
Mass
# of
Electrons
# of
Protons
# of
Neutrons
Element
Symbol
Atomic
Number
Atomic
Mass
# of
Electrons
# of
Protons
# of
Neutrons
Hydrogen
Oxygen
Sulfur
Gold
Lead
Element
Name
He
6
11
35.45
61
Answers
Element
Name
Element
Symbol
Atomic
Number
Atomic
Mass
# of
Electrons
# of
Protons
# of
Neutrons
Hydrogen
H
1
1.008
1
1
0
Oxygen
O
8
15.99
8
8
8
Sulfur
S
16
32.06
16
16
16
Gold
Au
79
196.96
79
79
118
Lead
Pb
82
207.2
82
82
125
Element
Symbol
Atomic
Number
Atomic
Mass
# of
Electrons
# of
Protons
# of
Neutrons
Helium
He
2
4.003
2
2
2
Carbon
C
6
12.01
6
6
6
Sodium
Na
11
22.990
11
11
12
Chlorine
Cl
17
35.45
17
17
18
Silver
Ag
47
107.87
47
47
61
Element
Name
Practice 2
Element/Isot
ope Name
Element
Symbol
Fluorine
F
Atomic
Number
Atomic
Mass
Electron
Number
Proton
Number
Neutron
Number
Argon -39
Neon-20
Neon-21
Neon-22
Hydrogen-1
Hydrogen-2
Hydrogen-3
-35
Cl
Chlorine-37
Carbon-12
Carbon-13
153
Answers
Element/Isot
ope Name
Element
Symbol
Atomic
Number
Atomic
Mass
# of
Electrons
# of
Protons
# of
Neutrons
Fluorine
F
9
18.998
9
9
10
Argon -39
Ar
18
39
18
18
21
Neon-20
Ne
10
20
10
10
10
Neon-21
Ne
10
21
10
10
11
Neon-22
Ne
10
22
10
10
12
Hydrogen-1
H
1
1
1
1
0
Hydrogen-2
H
1
2
1
1
1
Hydrogen-3
H
1
3
1
1
2
Chrlorin-35
Cl
17
35
17
17
18
Chlorine-37
Cl
17
37
17
17
20
Carbon-12
C
6
12
6
6
6
Carbon-13
C
6
13
6
6
7
Einstenium
Es
99
252
99
99
153
Unit 2 – Atomic Structure - Ions
Agenda:
•
•
•
•
•
Atomic Structure Quick Review
Phet Activity
Isotopes
Reading a Periodic Table Tile
Practice Determine # of
Subatomic Particles
Goal
• I will be able to use the periodic table
to determine the number of
subatomic particles present in an
atom of the MOST NATURALLY
ABUNDANT isotope for that element
Essential Question:
How can nuclei of the same element differ?
Monday
Tuesday
Wednesday
Thursday
Friday
No School
No School
Isotopes
Ions
Average Atomic
Mass
Atoms can lose or
gain electrons to
become Ions!
I’ve got my
Ion
you!
More Key Vocabulary
ION
Ion: atom with a plus or a minus charge.
Atom with a different number of protons and electrons.
two types
Cation: an atom with a positive charge.
Cation
Anion
•
•
Atom with more protons (+) than electrons (-)
Cats have paws….Cations are pawsitive…
Anion: an atom with a negative charge.
•
•
Atom with more electrons (-) than protons (+)
A negative ion, looks like onion (make you cry… is negative)
8
Protons:_______
O
Neutrons:______
Oxygen
Electrons:_____
16
Neutral Oxygen Atom
+1
+1
+1
+1
+1
+1
+1
+1
0
0
0
0
0
0
0
0
-1
-1
-1
-1
-1
-1
-1
-1
8
Protons:_______
O
Neutrons:______
Oxygen
Electrons:_____
16
O
Charge on this Atom?
1-
+1
+1
+1
+1
+1
+1
+1
+1
0
0
0
0
0
0
0
0
-1
-1
-1
-1
-1
-1
-1
-1
or
-1
O
-
8
Protons:_______
O
Neutrons:______
Oxygen
Electrons:_____
16
O
Charge on this Atom?
+1
+1
+1
+1
+1
+1
+1
+1
0
0
0
0
0
0
0
0
-1
-1
-1
-1
-1
-1
-1
-1
2-
-1
-1
3
Protons:_______
Li
Neutrons:______
Lithium
Electrons:_____
7
+1
0
-1
+1
0
-1
Neutral
Lithium
Atom?
If Lithium
loses an
electron?
+1
0
-1
0
+
Li
or
+1
Li
Na
+
+
2
Mg
Positive one charge means it has one less
electron (negative particle) than proton.
Two less electrons than protons.
Atoms lose or gain ELECTRONS!
PROTON NUMBER NEVER CHANGES!
1
F
3
N
One more electron than protons.
Three more electron than protons.
All of these atoms have something in common except for one
of them. Pick the Odd Man Out and explain why.
Ne
Odd Atom Out?
Na+
O2-
Justification?
F1-
N3-
Mg
Cation
o
r
Anion
Put these in the appropriate Column
2-
O
+
Li
An atom
that has lost
an electron.
An atom
that gained
an electron.
Write a mathematical
expression for determining
the charge on an atom.
Number of protons minus the number of electrons equals the charge on an atom.
#p - #e = charge
Practice 3
Protons
9
Protons
7
Protons
11
Protons
13
Electrons
10
Electrons
10
Electrons
10
Electrons
10
Charge
Charge
Charge
Charge
Symbol
Symbol
Symbol
Symbol
Protons
Protons
Protons
19
Electrons
Charge
Protons
20
Electrons
1+
Charge
2+
Electrons
18
Electrons
18
Charge
2-
Charge
1-
Symbol
Symbol
Symbol
Symbol
Protons
Protons
Protons
Protons
Electrons
Electrons
Electrons
Electrons
Charge
Charge
Charge
Charge
Symbol
Ba2+
Symbol
Cs1+
Symbol
Br1-
Symbol
P3-
18 8A
1 1A
Alkaline
Earth
Metals
Alkali
Metals
1
H
Transition
Lanthanides Actinides
Metals
Other
Metals
Metalloids
Other
Halogens
Nonmetals
Noble
Gases
2
http://www.vincentsapone.com
He
Helium
Hydrogen
1.0079
3
2 2A
1
Atomic Number
H
Element Symbol
4
Li
Be
Lithium
6.941
Beryllium
11
12
9.0122
Magnesium
19
20
24.305
5
Periodic
Table
Element Name
Atomic Mass
Hydrogen
1.0079
Na Mg
Sodium
22.990
13 3A
3
4
5
6
7
8
9
21
22
23
24
25
26
27
10
28
11
12
29
30
14
4A
6
15
5A
7
16 6A
8
17
8A
4.003
9
10
Ne
B
C
N
O
F
Boron
Carbon
Nitrogen
Oxygen
Fluorine
Neon
10.811
12.011
14.007
15.999
18.998
20.180
13
14
15
16
17
18
Al
Si
P
S
Cl
Ar
Aluminum
Silicon
Phosphorus
Sulfur
Chlorine
Argon
26.982
28.086
30.974
32.066
35.453
39.948
31
32
33
34
35
36
K
Ca
Sc
Ti
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
Ga
Ge
As
Se
Br
Kr
Potassium
39.098
Calcium
Scandium
Titanium
Vanadium
Chromium
Manganese
Iron
Cobalt
Nickel
Copper
Zinc
Gallium
Germanium
Arsenic
Selenium
Bromine
Krypton
40.078
44.956
47.88
50.942
51.996
54.938
55.933
58.933
58.693
63.546
65.39
69.732
72.61
74.922
78.09
79.904
84.80
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
Xe
Rb
Sr
Y
Zr
Rubidium
85.468
Strontium
Yttrium
Zirconium
Niobium
Nb Mo
87.62
88.906
91.224
92.906
95.94
55
56
72
73
74
Tc
Ru
Rh
Pd
Ag
Cd
In
Sn
Sb
Te
I
Ruthenium
Rhodium
Palladium
Silver
Cadmium
Indium
Tin
Antimony
Tellurium
Iodine
Xenon
98.907
101.07
102.906
106.42
107.868
112.411
114.818
118.71
121.760
127.6
126.904
131.29
75
76
77
78
79
80
81
82
83
84
85
86
Rn
Molybdenum Technetium
Cs
Ba
*
Hf
Ta
W
Re
Os
Ir
Pt
Au
Hg
Tl
Pb
Bi
Po
At
Cesium
132.91
Barium
57-71
Hafnium
Tantalum
Tungsten
Rhenium
Osmium
Iridium
Platinum
Gold
Mercury
Thallium
Lead
Bismuth
Polonium
Astatine
Radon
137.33
178.49
180.948
183.85
186.207
190.23
192.22
195.08
196.967
200.59
204.383
207.2
208.980
[208.982]
209.987
222.018
87
88
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
Fr
Ra
**
Rf
Db
Sg
Bh
Hs
Mt
Ds
Rg
Francium
[223]
Radon
89-103
Rutherfordium
Dubnium
Seaborgium
Bohrium
Hassium
[261]
[262]
[266]
[264]
[269]
[268]
[269]
[272]
[277]
unknown
[289]
unknown
[298]
unknown
unknown
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
La
Ce
[226]
Atomic mass in
[brackets] is for the
most stable isotope .
*
Lanthanum Cerium
140.115
138.906
89
**
90
Pr
Nd Pm Sm
Praseodymium Neodymium Promethium
Cn Uut
Meitnerium Darmstadtium Roentgenium Copernicium Ununtrium
Fl
Uup Lv
Uus Uuo
Flerovium Ununpentium Livermorium Ununseptium Ununoctium
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb
Lu
Samarium
Europium
Gadolinium
Terbium
Dysprosium
Holmium
Erbium
Thulium
Ytterbium
Lutetium
140.908
144.24
144.24
150.36
151.966
157.25
158.925
162.50
164.930
167.26
168.934
173.04
174.967
91
92
93
94
95
96
97
98
99
100
101
102
103
Cf
Es
Ac
Th
Pa
U
Np
Actinium
227.028
Thorium
Protactinium
Uranium
Neptunium
Plutonium
Pu Am Cm
Americium
Curium
Berkelium
Bk
232.038
231.036
238.029
237.048
244.064
243.061
247.070
247.070
Californium Einsteinium
251.080
[254]
Fm Md No
Lr
Fermium
Mendelevium
Nobelium
Lawrencium
257.095
258.1
259.101
[262]
Number of protons minus the number of electrons equals the charge on an atom.
#p - #e = charge
Answers
Protons
9
Protons
7
Protons
11
Protons
13
Electrons
10
Electrons
10
Electrons
10
Electrons
10
Charge
-1
Charge
-3
Charge
+1
Charge
+3
Symbol
F1-
Symbol
N3-
Symbol
Na+
Symbol
Al3+
Protons
19
Protons
20
Protons
16
Protons
17
Electrons
18
Electrons
18
Electrons
18
Electrons
18
Charge
1+
Charge
2+
Charge
2-
Charge
1-
Symbol
K+
Symbol
Ca2+
Symbol
S2-
Symbol
Cl1-
Protons
56
Protons
55
Protons
35
Protons
15
Electrons
54
Electrons
54
Electrons
36
Electrons
18
Charge
2+
Charge
1+
Charge
1-
Charge
3-
Symbol
Ba2+
Symbol
Cs1+
Symbol
Br1-
Symbol
P3-
# of Protons
Look at the Atomic Number
1. Round the Average Atomic
Mass to a Whole Number
In Summary
# of Neutrons
2. Subtract the Atomic Number
FROM the rounded Atomic Mass
3. # of Neutrons = Atomic Mass-Atomic Number
To determine
1. In a Neutral Atom,
Look at the Atomic Number
# of Electrons
a. If Positive Charge
[ Atomic Number- Charge]
2. In an Ion
b. If Negatively Charged
Charge on Atom
# protons #electrons =
Charge
[ Atomic Number + Charge]