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PERIODIC TABLEChapter 5
LIKE ALWAYS, START AT THE BEGINNING Until 1750, we only had 17 elements
discovered
1789- Antoine LavoisierGrouped by metals, non-metals, gas, earth
1860’s- Dmitri Mendeleev
THE VERY SCIENTIFIC PROCESS OF MENDELEEV He was a teacher, and
wanted to find a better way to describe the elements
Designed a periodic table in which elements were arranged in order of increasing atomic mass
Periodic -means repeating pattern
THE ARRANGEMENT Element’s Name
Mass
Properties: How they reacted
with Oxygen/Hydrogen
What do the symbols mean and numbers?
THE FINAL ARRANGEMENT Columns: by properties Rows: by mass
Periodic Table:An arrangement of elements in columns,
based on a set of properties that repeat from row to row
HOW MENDELEEV DID IT? He could not have a complete chart
Why? He had blanks, where he knew there
had to be something there but did not known what
EARLY BIRD DOESN’T ALWAYS GET THE WORM He was not the first to create a periodic
table or leave blanks in a tableHe did have the best explanation for it
Why was it the best? It was able to be used to make predictions
People had to fill in those blanks!Ex: Eka-aluminum and Gallium
What does this mean?
OUT WITH THE OLD… Mendeleev developed his table without
knowing there were protons…
From what we studied before why would this have been important?
Today’s periodic table is arranged by atomic number!
PERIODS AND GROUPS Periods (Go from 1 to 7)
Rows of the periodic table (horizontal)(L-R)
GroupsEach column (up-down) on the tableThe elements within a group have similar
properties but not identical
The repeating pattern of chemical and physical properties when atomic number is used to arrange is the periodic law.
FOUR PIECES OF INFORMATION ON THE PERIODIC TABLE Atomic number Element Symbol Element Name
Atomic Mass: Value depends
on average mass of the isotopes and their distribution in nature
ATOMIC MASS Depends on the average of isotopes of an
element. Example: The AM of chlorine is 35.453. How was this determined? How many isotopes does chlorine have? Chlorine -35 and Chlorine -37.
Chlorine -35 is 75.78% Chlorine -37 is 24.22%
The average of these percents is 35.453.
ATOMIC MASS UNIT The unit assigned to the mass of an
element
Too small to use grams since anything we measure contains 1000’s to 1,000,000s of atoms
Atomic Mass Unit (AMU)- based on 1/12th of a carbon atom
HOW TO CLASSIFY ELEMENTS1. Solids, liquids, gases
2. Natural and Synthetic Natural: Forms in nature Synthetic: Man-made element
3. Properties: Metals, Nonmetals, metalloids
METALS Majority of elements on table Good conductors of heat/electricity Most are solid at room temp.
Mercury (Hg) Most are malleable (hammered) and
ductile (can be formed into wire) Some react, some don’t
TRANSITIONAL METALS Still classified as metals but have even
more special properties
Noticeable property: They make very distinctive colors
More on these next chapter…
NONMETALS Properties are opposite of metals Poor conductors Most are gases at room temp. If solid, they are very brittle (fragile) Extremely reactive
METALLOIDS The elements in between metals and
nonmetalsEx: They can be conductive at the right
temperaturesSilicon: Used in Computer Chips
TRENDY ELEMENTS Elements to the left of the dark line are
Metals Elements to the right of the dark line are
Nonmetals
As you go from left to right you go from highest metallic properties to more nonmetallic properties
METALS, NONMETALS, & METALLOIDS
1
2
3
4
5
6
7
Metals
Metalloids
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 349
Nonmetals
THE PERIODIC TABLE
Li
3
He
2
C
6
N
7
O
8
F
9
Ne
10
Na
11
B
5
Be
4
H
1
Al
13
Si
14
P
15
S
16
Cl
17
Ar
18
K
19
Ca
20
Sc
21
Ti
22
V
23
Cr
24
Mn
25
Fe
26
Co
27
Ni
28
Cu
29
Zn
30
Ga
31
Ge
32
As
33
Se
34
Br
35
Kr
36
Rb
37
Sr
38
Y
39
Zr
40
Nb
41
Mo
42
Tc
43
Ru
44
Rh
45
Pd
46
Ag
47
Cd
48
In
49
Sn
50
Sb
51
Te
52
I
53
Xe
54
Cs
55
Ba
56*
Hf
72
Ta
73
W
74
Re
75
Os
76
Ir
77
Pt
78
Au
79
Hg
80
Tl
81
Pb
82
Bi
83
Po
84
At
85
Rn
86
Fr
87
Ra
88Y
Rf
104
Db
105
Sg
106
Bh
107
Hs
108
Mt
109
Mg
12
Ce
58
Pr
59
Nd
60
Pm
61
Sm
62
Eu
63
Gd
64
Tb
65
Dy
66
Ho
67
Er
68
Tm
69
Yb
70
Lu
71
Th
90
Pa
91
U
92
Np
93
Pu
94
Am
95
Cm
96
Bk
97
Cf
98
Es
99
Fm
100
Md
101
No
102
Lr
103
La
57
Ac
89
1
2
3 4 5 6 7
* Lanthanides
Y Actinides
Noblegases
Halogens
Transition metals
Alkalineearth metals
Alk
ali m
etal
s
8 9 10 11 12
13 14 15 16 17
18
Uun
110
Uuu
111
Uub
112
Uuq
113
Uuh
116
Uuo
118
VALENCE ELECTRONS Def: An electron that is in the highest
occupied energy level
Critical when dealing with chemical reactions
Elements in the same group are based off these valence electrons
ALKALI METALS Group on the far right (1A)
List the elements in this group as HW.
Have a single valence electron and are extremely reactive
All elements in this group are metals
Not all have the same amount of reactivity. As you go down the chart, the reactivity increases.
ALKALINE EARTH METALS Group 2A All have 2 valence electrons Harder and higher melting pt. than 1A All metals
Differences in reactivity are shown by how they react with water.
MAGNESIUM Key process in photosynthesis
Process plants go through to take sunlight and turn it into usable energy
Its in the center of chlorophyll
Magnesium is light but strong which makes it good for transporting molecules in the plant cell
Also used for bikes and backpack frames
CALCIUM Bones and teeth strong
Milk!
Calcium CarbonateFound in chalk, coral, limestone, and even
in your toothpaste
Calcium Sulfate: A cast
BORON FAMILY Group 3A Three valence electrons 1 metalloid, 4 metals
Contains Aluminum!Most abundant metal in Earth’s Crust
PRODUCTS MADE IN BORON FAMILY Aluminum
10% is in packagingParts in cars and airplanesWindow framesRecyclable!
Boron: Used in special glassware to not shatter when undergoing quick temp. changes
CARBON FAMILY Group 4A Contains 4 valence electrons 1 nonmetal, 2 metalloid, 2 metals
Important: Life wouldn’t exist without carbon
NITROGEN FAMILY Group 5A 5 Valence Electrons 2 nonmetals, 2 metalloids, 1 metal
Most two important elementsNitrogen and Phosphorus
USES FOR NITROGEN FAMILY Fertilizers: uses nitrogen and
phosphorusWhy?Soil has nutrients (Items needed to survive)Sometimes soil doesn’t have enoughFertilizers gives nutrients to soil so plants
can useWhy plants need: Proteins and DNA
OXYGEN FAMILY Group 6A 6 Valence Electrons 3 nonmetals, 2 metalloids
Oxygen is the most abundant element in the Earth’s crust
OXYGEN Needed by life to release energy
Can be stored as liquid in oxygen tanksNo flammable stuff near them
Ozone: Harmful at ground levelProtects us in the atmosphere
SULFUR One of the 1st elements discovered
Main use: Sulfuric AcidMost produced chemical in US65% of it is used to make fertilizer
HALOGENS Group 7A 7 Valence electrons 4 nonmetals, 1 metalloid
Highly reactive (Top highest)
Different physically, similar chemically
USES OF FLUORINE AND CHLORINE Fluorine
Toothpaste (prevents tooth decay)Cooking spray (non-stick)
ChlorineWashingSterilizing (Killing bacteria)
IODINE Iodine is needed in your body to keep
your thyroid gland workingGland is in charge of reactions in your body
Seafood has Iodine
Fresh fish wasn’t available we made Iodized Salt
NOBLE GASES Group 8A Contains 8 Valence Electrons (He:2) 6 nonmetals
Colorless, Odorless, Not reactive
USES OF NOBLE GASES Used in situations where oxygen and
hydrogen is highly reactive with a substance
Bulbs are filled with these gases because oxygen would react at that temp.