Transcript The Periodic Table - River Dell Regional School District

The Periodic Table
I. History
II. Arrangement of Elements
III. Electron Configuration
Trends
IV. Periodic Trends
V. Reactivity
A. Johann Dobreiner’s Law of Triads in
1817
B. John Newlands – Law of Octaves
C. Lothar Meyer (1835-1895 - German)
Properties of elements show a
repetitive pattern when they are
arranged by atomic mass
D.Dimitri Mendeleev (1834-1907- Russian)
(father of modern periodic table)
Published system used today (1869)
2. Elements arranged by increasing mass
3. Left spaces for elements not yet
discovered - predicted properties
(scandium, gallium, germanium)
Dimitri Mendelev
Mendeleev’s Table
His table re-organized
Mendeleev’s Periodic Table
E. Henry Mosley (1887-1915) English
1.Arrange elements
by increasing atomic
number – this led to the
periodic law
2. Periodic Law - properties
of elements are periodic
functions of their atomic #
periodic repetition of
physical and chemical
properties
II. Arrangement of Elements
A. Periodic Table – arrangement of
elements in order of increasing
atomic number so that elements with
similar properties are in the same
column
period – horizontal row (7)
group(family)- vertical columns (1-18)
periodicity – reoccurrence of similar
properties of elements in groups
C. Special Groups on the Periodic Table
Periodic Table
D. Periodic Table Showing s,p,d,f Blocks
E. Metals – Metalloids - Nonmetals
1. Metals are on the left side – all are solids
except mercury (Hg)
a. elements near the left of a period are more
metallic than those near the right
b. elements near the top of a group are more
metallic than those near the bottom
2. Metalloids – group of elements between
metals and nonmetals(B,Si,Ge,As,Sb,Te)
3. Nonmetals are on the right side – all are
solids or gases except bromine(Br) liquid
Metals – Metalloids - Nonmetals
PROPERTY
Luster
Deformability
METAL
NONMETAL
high
malleable
and ductile
Conductivity
good
Electron gain/lose lose
Ion formed
cation (+)
Ionization energy low
Electronegativity low
low
brittle
poor
gain
anion(-)
high
high
IV.Periodic Trends(Main Group Elements)
A. Atomic Radii
1. atomic radius is ½ the distance
between nuclei of identical atoms
joined in a molecule
2. decreases across periods (left-right)
a. caused by increasing attraction
between protons and electrons
3. increases from top to bottom
a. caused by adding electrons to
new shells
What is the atomic radius?
Atomic radii include
the region in which
electrons are found
90% of the time
Atomic Size
}
Radius
• Atomic Radius = half the distance between two
nuclei of a diatomic molecule.
Periodic Trends in Atomic Radii
Periodic Trends in Atomic Radii
Trends in Main Groups
Atomic Radii
Period Trends
A. Periodic Trends in Atomic Radii
B. Ionization Energy
1. Energy required to remove an electron
from an atom of an element (KJ/mol)
2. Increases across periods (left to right)
a. result of increased nuclear attraction
3. Decreases down groups (families)
a. electrons added to higher energy levels
b. shielding effect of inner shell electrons
c. repulsion of inner shell electrons
4. Energy to remove second and third
electron is greater
B. Trend in Ionization Energy
B. Periodic Trends in Ionization Energy
Symbol First
H
He
Li
Be
B
C
N
O
F
Ne
1312
2731
520
900
800
1086
1402
1314
1681
2080
Second
5247
7297
1757
2430
2352
2857
3391
3375
3963
Third
11
810
14840
3569
4619
4577
5301
6045
6276
C. Electronegativity
1. Measures how strongly one atom
attracts the electrons of another atom
when they form a compound
2. Increases across periods (left to right)
a. Fluorine has greatest value of 4
3. Decreases down groups
a. electrons far from the nucleus in
larger atoms have less attraction
b. Cesium and Francium with large radii
have the smallest electronegativity
Periodic Trends in Electronegativity
C. Periodic Trends in Electronegativity
C. Periodic Trends in Electronegativity
D. Ionic Radii
1. Ion – atom that acquires a charge by
gaining or losing electrons
a. cation (+) ion
anion (-) ion
2. Period trends
a. cation radii decrease across periods
b. anion radii increase across periods
3. Group trends
a. increase in cation and anion radii
down groups
Formation of an Anion (- ion)
D. Comparison of Atomic and Ionic Radii
D. Periodic Trends in Ionic Radii
E. Electron Affinity
1. Energy change that occurs when an electron is
added to a neutral atom
2. If it is easy to add an electron to an
atom the energy value is negative
a. halogens have large negative values
3. If it is difficult to add an electron to an
atom the energy value is positive
a. atoms in groups 2 and 18 have high
positive values (due to filled subshells)
b. usually higher values in larger atoms
Electron Affinity for Chlorine
Periodic Trends in Electron Affinity
Periodic Trends in Electron Affinity
PERIODIC TRENDS
Periodic Trends in Melting Point
Periodic Trends in Density
V. Reactivity
A. Reactivity – measure of the tendency
of an element to engage in chemical
reactions by losing, gaining or
sharing electrons
1. atoms of reactive elements are very
likely to gain, lose or share electrons
2. atoms of reactive elements are likely
to form chemical bonds with other
elements
B. Reactivity and the Periodic Table
1. alkali metals (group 1) most reactive
metals
2. alkaline earth metals (group 2)
second most reactive group of metals
3. halogens (group 17) most reactive
nonmetals
4. noble gases (group 18) least reactive
C.Ionization Energy and Electronegativity
1. elements with very high and very
low values are very reactive
Electron Arrangement and Reactivity
Electron Configuration
• S block [groups 1 and 2]
• P block [groups 13,14,15,16,17,18]
• D block [groups 3,4,5,6,7,8,9,10,11,12]
• F block (lanthanide and actinide series)
H
Li
1
1s1
group 1
1s22s1
3
Na
11
K
19
Rb
37
Cs
55
Fr
87
1s22s22p63s1
1s22s22p63s23p64s1
1s22s22p63s23p64s23d104p65s1
1s22s22p63s23p64s23d104p65s24d10
5p66s1
1s22s22p63s23p64s23d104p65s24d105p6
6s24f145d106p67s1
S- block
s1
s2
• Alkali metals all end in s1
• Alkaline earth metals all end in s2
• Should include He but helium has
the properties of the noble gases.
- its outer shell is filled with the
maximum number of electrons
allowed for the first shell (2)
He
2
1s
2
Ne
2
2
6
1s 2s 2p 10
Ar
2
2
6
2
6
1s 2s 2p 3s 3p
18
Kr
2
2
6
2
6
2
10
6
1s 2s 2p 3s 3p 4s 3d 4p
36
1s22s22p63s23p64s23d104p65s24d105p6
Xe
54
1s22s22p63s23p64s23d104p65s24d10
5p66s24f145d106p6
Rn
86
The P-block
p1 p2
p3
p4
p5
p6
Transition Metals -d block
d1 d2 d3
s1
d5
s1
d5 d6 d7 d8 d10 d10
F - block
• inner transition elements- hold a maximum
of 14 therefore there are 14 elements in
both the actinides and lanthanides
f1 f2 f3 f4 f5 f6 f7 f8 f9 f10 f11 f12 f13 f14
Group
•
•
•
•
•
•
•
•
Ion Formed
Group 1
Group 2
Group 13
Group 14
Group 15
Group 16
Group 17
Group 18
X+
X2+
X3+
Xvaries
X3X2XX0
Electron Changes
•
•
•
•
•
•
•
•
Loses 1 electron
Loses 2 electrons
Loses 3 electrons
Varies
Gains 3 electrons
Gains 2 electrons
Gains 1 electron
Does not gain or
lose electrons