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