Chapter 3: Atoms & Elements
Mixtures & Pure Substances
Elements & Symbols
The Periodic Table
Atomic Structure
Isotopes
Electron Energy Levels
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Matter
The stuff things are made of.
Has Mass and takes up space.
(Air, water, rocks, etc..)
The amount of stuff (in g’s)
(Bowling Ball > Balloon)
Weight on earth.
Pull of Gravity on matter.
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Classification of matter
Matter
Pure Substance
Element
Fe
Mg
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Mixture
Compound
FeS
Fe + S
MgO
Mg + O2
2-3
Mixtures
Mixture
Homogeneous
(Solution)
Uniform composition
Heterogeneous
Non-uniform composition
Air
Gasoline
Pizza
Fe + S
Urine
Tea w/ice
Sand
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Atomic Symbols
Nitrogen
Hydrogen
Nickel
Aluminum
Bromine
Each element is assigned a unique symbol
1-2 letters; 1st is capitalized
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Sodium (Natrium)
Atomic Symbols
Potassium (Kalium)
Silver (Argentum)
Iron
(Ferrum)
Gold (Aurum)
Lead
(Plumbum)
The original name is often of Latin or Greek origin
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Atomic Symbols
Carbon
Calcium
Chromium
Cobalt
Copper (Cu)
Chlorine
Elements with same starting letter, get
second letter added to the symbol
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Periodic Table: Groups
Alkali Metals
Alkaline Earth Metals
IA
H
Noble gases
II A
Transition Metals
Na Mg III B IVB V B VIB VIIB
Ca Sc Ti
Rb Sr
VIIIA
III A IV A V A VI A VIIA
Li Be
K
Halogens
Y
V
VIII B
IIB
B
C
N
O
F
Ne
Al
Si
P
S
Cl Ar
Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te
Cs Ba Ls Hf Ta W Re Os Ir
Fr Ra Ac
IB
He
I
Xe
Pt Au Hg Tl Pb Bi Po At Rn
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np Pu AmCm Bk Cf Es Fm Md No Lr
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Periodic Table: Periods
Periods are
assigned numbers
1
H
2
Li Be
B
C
N
O
F
3
Na Mg
Al
Si
P
S
Cl Ar
4
K
5
Rb Sr
6
Cs Ba Ls Hf Ta W Re Os Ir
7
Fr Ra Ac
Ca Sc Ti
Y
V
He
Ne
Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te
I
Xe
Pt Au Hg Tl Pb Bi Po At Rn
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
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2 - 10
Metals
Lustrous, malleable and ductile.
Conductors (heat & electricity)
H
Solids at room temp (except Hg)
He
Li Be
Lose electrons to non-metals.
B C N O F
Ne
Na Mg
K
Al
Ca Sc Ti
Rb Sr
Y
V
P
S
Cl Ar
Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te
Cs Ba Ls Hf Ta W Re Os Ir
Fr Ra Ac
Si
I
Xe
Pt Au Hg Tl Pb Bi Po At Rn
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
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Non-metals
H
He
Li Be
B
C
N
O
F
Na Mg
Al
Si
P
S
Cl Ar
K
Ga Ge As Se Br Kr
Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn
Gas,
liquid, solid (dull, brittle)
Zr Nb Mo Tc Ru Rh Pd Ag Cd
Poor Yconductors
= Insulators
Rb Sr
In Sn Sb Te
Cs Ba Ls Hf Ta W Re Os Ir
Pt Au Hg
Many are diatomic molecules.
Tl Pb Bi Po At Rn
Pr Nd Pm Sm Eu Gd Tb
Gain e’s from Ce
metals
Dy Ho Er Tm Yb Lu
Fr Ra Ac
I
Ne
Xe
Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
Share e’s with other non-metals
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Metaloids
H
He
Li Be
B
C
N
O
F
Na Mg
Al
Si
P
S
Cl Ar
K
Ca Sc Ti
Rb Sr
Y
V
Ne
Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te
Intermediate properties
Cs Ba Ls Hf Ta W Re Os Ir
I
Xe
Pt Au Hg Tl Pb Bi Po At Rn
Semi conductors
Fr Ra Ac
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
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Metals
Non-metals
Metaloids
H
He
Li Be
B
C
N
O
F
Na Mg
Al
Si
P
S
Cl Ar
K
Ca Sc Ti
Rb Sr
Y
V
Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te
Cs Ba Ls Hf Ta W Re Os Ir
Fr Ra Ac
Ne
I
Xe
Pt Au Hg Tl Pb Bi Po At Rn
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
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A model of matter
Atom - The smallest unit of an
element that is still that element.
ie. Aluminum (Al)
Molecule -The smallest unit of a
pure substance that is still that
substance.
May contain > 1 atom or element.
ie. Water (H2O)
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Structure of the atom
Nucleus =
Small, dense, + charge in the center
of an atom.
contains
protons
&
+
+
+
+
+ +
neutrons
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Structure of the atom
Nucleus
Electrons
- charged particles
that surround the
nucleus.
Electrons move around
nucleus in orbitals.
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Structure of the atom
The nucleus is a small part of an atom.
If the nucleus was the size
of a marble, the atom would
fill a football stadium.
The nucleus would weigh
over 10,000 tons.
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The atomic symbol
A = Atomic mass (amu)
= # protons + # neutrons
A
Z
-
X
Z = Atomic number
+
-
= # protons = # electrons
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-
+
+
-
+
+
+
2 - 19
The atomic symbol
A = Atomic mass
= # protons
+ # neutrons
6
6
-
12
6
X
Z = Atomic number
+
-
= # protons = # electrons
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-
+
+
-
+
+
+
2 - 20
The atomic symbol
A = Atomic mass
= # protons + # neutrons
12
6
C
Z = Atomic number
+
-
= # protons = # electrons
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-
+
+
-
+
+
+
2 - 21
The atomic symbol
A = Atomic mass
= p + n = 23
23
Na
11
Z = Atomic # = p = 11
Sodium
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Why is the atomic weight on the tables
not a whole #?
47
Silver
Ag
107.87
Atomic number
Name of the element
Elemental Symbol
Atomic mass (weight)
Atomic weight = The average, relative
mass of an atom in an element.
Isotopes of Hydrogen
Isotopes = Atoms of the same element but
having different masses.
1
2
3
H
H
H
1
1
1
+
Protium
99.99%
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-
+
Deuterium
0.01%
+
Tritium
Trace %
2 - 24
Isotopes of Hydrogen
Isotopes = Atoms of the same element but
having different masses.
1
2
3
H
H
H
1
1
1
+
-
+
+
Average Atomic weight of Hydrogen
= 1.00794 amu
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Isotopes of Carbon
12
C
6
-
-
+
+
13
C
6
-
-
-
+
+
+
+ +
-
98.89%
-
+
+
+ +
-
-
+
14
C
6
- -
1.11%
+
-
-
+
-
+
+
+ +
-
-
Trace %
Average Atomic weight of C= 12.011 amu
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Radioactive Isotopes
14
C
6
3
H
1
-
-
+
+
Nucleus is unstable
So falls apart (decays)
Giving radioactive particles
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-
+
-
+
+
+ +
-
-
2 - 27
The atomic symbol & isotopes
Determine the number of protons, neutrons
and electrons in each of the following.
31
15 P
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138
56
Ba
238
92
U
2 - 28
Atomic Structure
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Symbol
At#
Mass
____
Be
____
4
____
9
Cl
____
17
37
Si
____
14
____
28
P
N
4
5
e-
___
4
___
17 ___
20 ___
17
___
14 14
14
___
2 - 29
Electron arrangement
24
Mg
12
Electrons
fill layers
around
nucleus
32 Low  High
18
A new layer is
8
added for each
2
row or period
in the table.
Shells = Energy levels
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IA
IIA
1
H
1
7
Li
3
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4
He
2
9
Be
4
2 - 31
IA
IIA
IIIA
1
H
1
7
Li
3
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9
Be
4
11
5B
2 - 32
IIIA
11
5B
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IVA
12
6C
VA
13
7N
2 - 33
IA
IIA
1
H
1
7
Li
3
23
Na
11
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VIIIA
4
He
2
9
Be
4
20
10Ne
24
12Mg
40
18Ar
2 - 34
1
H
1
7
Li
3
23
Na
11
1
9
Be
4
24
12Mg
Valence electrons
Where most chemical
Reactions occur.
2
3
11
5B
27
13Al
Inner electrons: No rxns if normal conditions.
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Inner vs. valence electrons
Valence electrons
This is where
most chemical
reactions
occur.
Inner electrons
Not much happens
here under normal
conditions.
With added energy inner electrons jump to
higher levels, then fall back giving E
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1
8
1
H
1
7
Li
3
23
Na
11
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2
4
He
2
9
Be
4
20
10Ne
24
12Mg
40
18Ar
2 - 37
1
H
1
7
Li
3
23
Na
11
Lewis Structures
H
Li
Show only
Valence
Electrons
Na
K
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Atoms and Molecules - Chemeketa Community College