Notes: 6.1 & 6.2
• OBJECTIVES: Students will be able to (SWBAT)
1. Explain how the periodic table was developed
2. Identify key features of the periodic table
3. Explain why elements in the same group have similar 3. Explain why elements in the same group have similar
properties
• 7 lecture Q’s (and 8 Reading Q’s)
• 5-sentence summary
Development of the Modern Periodic
Table (Chapter 6, Section 1)
The History of the Periodic Table
LAVOISIER NEWLANDS MEYER MENDELEEV MOSELEY
WHEN (YEAR)
Pages 151 – 153
WHAT
(DISCOVERIES)
The History of the Periodic Table
LAVOISIER NEWLANDS MEYER MENDELEEV MOSELEY
WHEN (YEAR)
Pages 151 – 153
1790’s 1864 1869 1869 1913
WHAT
(DISCOVERIES)
The History of the Periodic Table
LAVOISIER NEWLANDS MEYER MENDELEEV MOSELEY
WHEN (YEAR)
Pages 151 – 153
1790’s 1864 1869 1869 1913
WHAT
(DISCOVERIES)
Compiled
a list of
23 known
elements
Law of
Octaves –
repeating
pattern of 8
elements by
atomic
mass
Made
connection
between
atomic mass
and
properties of
elements
1st credited
with creating
a useful
periodic table;
predicted yet
to be
discovered
elements
Organized
elements by
atomic
number�
PERIODIC
LAW
The History
• History of the Periodic Table
– Lavoisier – 1700’s; listed 23 known elements at the time
– Newlands – created the Law of Octaves (or eight)
• Organized elements by atomic mass and saw that chemical properties repeat every 8 elements (repeating pattern is called periodic)
– Meyer, Mendeleev and Moseley � Modern Periodic – Meyer, Mendeleev and Moseley � Modern Periodic Table
• Mendeleev (father of the first Modern Periodic Table) –arranged by increasing atomic mass and in columns by similar chemical properties
• Moseley – arranged table by increasing atomic number
(number of protons) which corrected some of the errors in Mendeleev’s table
Repeating (periodic) pattern of 8
The problem…
…and later still…
The Modern Periodic Table
• Periodic Law: repetition of chemical and physical
properties of elements arranged by increasing
atomic number
• Arrangement and Organization
– Refer to your periodic table handout– Refer to your periodic table handout
The Modern Periodic Table“A” groups – REPRESENTATIVE ELEMENTS
“B” groups – TRANSITION ELEMENTS
NONMETALS→
“staircase”←METALS
On staircase – METALLOIDS or SEMIMETALS
Element →
Atomic number →
Symbol →
Atomic Mass →
←State of matter
Pages 156-157
Periods
(rows)
Groups
(columns)
↓
(rows)
→
METALSNON-
METALS
METALLOIDS
Types of Metals and Nonmetals
• Most elements are metals
– Alkali metals (group 1A, except Hydrogen)
– Alkaline earth metals (group 2A)
– Transition metals (all group B’s)– Transition metals (all group B’s)
– Inner Transition metals (f-block elements)
– Halogens (group 7A)
– Noble gases (group 8A)
Alkali
metals
Alkaline
Earth
metals
Transition
metals
Halogens
Noble
gases
Inner Transition
metals
Inner Transition Metals (f-block)
• #58 (cerium) starts after Lanthanum (La; #57)
– From Ce to Lu
– Called the LANTHANIDE SERIES
___________
• #90 (thorium) starts after Actinium (Ac; #89)
– From Th to Lr
– Called the ACTINIDE SERIES
_______
Classification of the Elements (Chapter
6, Section 2)
Organization of Elements by Electron Configuration
• Similar chemical properties are due to same
number of valence e-
– Same group � same # of valence e- � similar chemical
and physical properties
• Valence electrons by group number (only for
representative or A group elements)representative or A group elements)
– Example: Group 1A (alkali metals) � e- config ends in s1
� 1 valence e-
• Valence electrons by period number
– Example: Period 3 elements have valence electrons in
the highest energy level � level 3
Valence electron configurations
• s2p5 are all the elements in group 5A because
they all end with electron configurations of
s2p5 � this represents the valence or outer
electron configurationelectron configuration
– F � 1s22s22p5
– Cl � 1s22s22p63s23p5
– Br � 1s22s22p63s23p64s23d104p5
– I � 1s22s22p63s23p64s23d104p65s24d105p5
All of the above elements are
in group 7A and have 7
valence e- � halogens
Period 2 � highest level is 2
Period 3 � highest level is 3
Period 4 � highest
level is 4
Period 5 � highest
level is 5
Elements in the same group have
similar Lewis Dot Structures
The s, p, d and f Block Elements
• The s, p, d and f Block Elements
– s-block (groups 1A and 2A) – alkali & alkaline
earth
– p-block (groups 3A - 8A) – mostly nonmetals, – p-block (groups 3A - 8A) – mostly nonmetals,
halogens and noble gases
– d-block (the B groups) – transition metals
– f-block – inner transition metals
Tell me the GROUP, PERIOD and BLOCK
• [Ne]3s23p5
GROUP: 7A
PERIOD: 3
BLOCK: p
List all the elements with the following valence
electron configurations. What are the group
numbers? What type of element are they?
1) s2
2) s2d1
Be, Mg, Ca, Sr, Ba, Ra
Sc, Y, La, Ac
Group 2A Alkaline earth metals X
2) s2d1
3) s2p 6
Group 3B
Sc, Y, La, Ac
Ne, Ar, Kr, Xe, Rn
Group 8A
Transition metals
Noble Gases X