Trends in periodic table

1. Created and Published by Mayur Patel
Department of Chemistry (2013-2014)
High School Attached to Harbin Institute of Technology
Page1
Unit 9 – The Periodic Table
An Element is made up of only one type of atoms.
Arranging all the elements by their atomic number and their properties led to the creation of…
…the Periodic Table
The vertical columns of elements are called “Groups”
The horizontal rows of elements are called “Periods”
The group number indicates “How many electrons in the outermost shell”
The period number indicates “How many (total number) shells the atom has”
The elements of the periodic table can be divided into
Metals Non-Metals
Shiny Dull
Sonorous (Make sound) Non-sonorous
High Melting & boiling point. Except
Hg is a liquid
Low Melting & boiling point. Except Br2
is a liquid
High Density ( Feel Heavy) Low Density (Feel Light)

2. Created and Published by Mayur Patel
Department of Chemistry (2013-2014)
High School Attached to Harbin Institute of Technology
Page2
Strong Not Strong
Malleable (Changed into sheets) Not Malleable
Ductile (Changed into wires) Not Ductile
Conduct Heat Do not conduct Heat
Conduct Electricity Do not Conduct Electricity (Except.
Graphite)
Classification of Elements in the Periodic Table

3. Created and Published by Mayur Patel
Department of Chemistry (2013-2014)
High School Attached to Harbin Institute of Technology
Page3
Define the following:
Atom ……………………………………………………………………………………………………………………………………………
Element …………………………………………………………………………………………………………………………………………
Halogen………………………………………………… an example of one is __________ (___)
Nobel Gas ………………………………………… an example of one is _________ (____)
Compound ………………………………………… an example of one is _________ (____)
In the Periodic Table………
Reaction
Reactants
Products
Chemical Properties
反应
反应物
产物
化学性质
Physical Properties
Tendency
Valence electrons
Solution
物理性质
趋势
价电子
溶液

4. Created and Published by Mayur Patel
Department of Chemistry (2013-2014)
High School Attached to Harbin Institute of Technology
Page4
Trends in Group 1 – The alkali metals
They are all metals and Mono-atomic
1) All elements have 1 electron in the outer shell:
Eg: Li: 2,1 Na: 2,8,1 K: 2,8,8,1 etc
2) So they tend to loose electrons and form +1 ions (Cations)
Eg: are Li+
, Na+
, K+
etc.
3) All elements are
Shiny, Light in weight & Soft
(Li, Na & K are very soft that can
be cut with knife)
4) The melting point of Group I elements decreases down the group.
Element Atomic number Melting point (o
C)
Lithium 3 180
Sodium 11 98
Potassium 19 63
Rubidium 37 39
Casesium 55 29

5. Created and Published by Mayur Patel
Department of Chemistry (2013-2014)
High School Attached to Harbin Institute of Technology
Page5
5) Reaction of Group I elements with water
2Li (s) + 2H2O (l) 2LiOH (aq) + H2 (g)
2Na + 2H2O 2NaOH + H2
K + __________________________________
Rb + _________________________________
All of them react vigorously with water giving hydrogen gas and an alkaline solution of
the hydroxide.
More difficult to loose electron so less reactive
More easy to loose electron So more reactive

6. Created and Published by Mayur Patel
Department of Chemistry (2013-2014)
High School Attached to Harbin Institute of Technology
Page6
Trends in Group 7 – The Halogens
They are nonmetals and Diatomic
1) All elements have 7 electrons in the outer shell:
F: 2,7 Cl: 2,8,7 Br: 2,8,18,7 etc.
2) So they tend to gain electrons and form -1 ions (Anions)
Eg: are F-
, Cl-
, Br-
etc.
3)
PHYSICAL STATE COLOR
Fluorine Gas Yellow
Chlorine Gas Green
Bromine Liquid Brown
Iodine Solid Black
4) The melting point of Group 7 elements increases down the group.
Element Atomic number Melting point (o
C)
Fluorine 9 -220
Chlorine 17 -101
Bromine 35 -7
Iodine 53 113
C
L
O
R
I
N
E

7. Created and Published by Mayur Patel
Department of Chemistry (2013-2014)
High School Attached to Harbin Institute of Technology
Page7
5) Displacement reaction of Halogens
A more reactive Halogen will DISPLACE a less reactive Halogen from a solution of its
salt.
This is called Displacement Reaction.
More easy to gain electron So more reactive
More difficult to gain electron So less reactive

8. Created and Published by Mayur Patel
Department of Chemistry (2013-2014)
High School Attached to Harbin Institute of Technology
Page8
The Transition Metals

9. Created and Published by Mayur Patel
Department of Chemistry (2013-2014)
High School Attached to Harbin Institute of Technology
Page9
The compounds of transition elements have different charges.
e.g. Iron can be Fe2+
or Fe3+
,
Copper can be Cu+1
or Cu+2
Manganese can be Mn+1
, Mn+2
......... Mn+7
Red Orange Yellow Turquoise Blue Purple
Co(NO3)2 K2Cr2O7 K2CrO4 NiCl2 CuSO4 KMnO4
Many of the transition elements and compounds are used as CATALYSTS.
Catalyst: A catalyst is a substance that increases the rate of reaction without taking part
in the reaction

10. Created and Published by Mayur Patel
Department of Chemistry (2013-2014)
High School Attached to Harbin Institute of Technology
Page10
The Noble Gases/ Inert Gases
All of them are UNREACTIVE!
Because they have no tendency to loose or gain electrons!
Element Uses
He Used in Baloons
Ne Used in advertising signs and car
lights
Ar Used in Bulbs
Used in welding