Pages in this set

Page 1

Preview of page 1

Page 2

Preview of page 2
The History of the Periodic Table:

Early 1800's:
-Elements were arranged in order of atomic mass
-Scientists had no idea about atomic structure

Alexander NEWLAND-1864:
-Noticed every 8th element had similar properties
-Arranged tables in rows of 7 Newland Octaves
-Problems:
-No gaps left for undiscovered elements
-Metals and non-metals…

Page 3

Preview of page 3
K
Rb
Cs
Fr
The Modern Periodic Table is Based on:
-Electronic structure Making it easier to predict properties
-Shells Corresponding to energy levels
-The further away an electron is from the nucleus the less of an attraction it has to it
-Lots of inner electrons causes SHEILDING=Electrons getting in…

Page 4

Preview of page 4
Group 7:
-Halogens (non-metals with coloured vapours)
-7 outer electrons
-Molecules consists of PAIRS OF ATOMS
-As you go down elements get LESS REACTIVE and have a HIGHER BOILING AND MELTING POINTS

Group 7
Other Properties Colour
Element

Fluorine Very reactive YELLOW GAS
Poisonous

Chlorine Fairly reactive GREEN GAS
Poisonous…

Page 5

Preview of page 5
Cl
Br
I
At




Halogens:
-Form IONICS BONDS with METALS producing 1¯ ions called HALIDES (NaCl)
-More reactive halogens DISPLACE less reactive ones from an AQEOUS SOLUTION of its salt




Transition Metals: In between Group 2 and 3

Page 6

Preview of page 6

Page 7

Preview of page 7
-Good conductors of heat and electricity
-Dense, strong and shiny
-Don't react vigorously with water or oxygen (unlike Group 1 metals)
-Denser, stronger and harder than Group 1 metals
-Have higher melting points than Group 1 metals
-Often have more than 1 ion different number of ions form different colours…

Page 8

Preview of page 8

Page 9

Preview of page 9
-Caused by dissolved Ca² and Mg² ions
- Dissolved calcium and magnesium ions react with soap to make scum
-Need more soap to produce good lather
-When heated/boiled it forms scale on the inside of the appliance reducing its efficiency so things like heating pipes or boilers may need to…

Page 10

Preview of page 10
Both Types of Hardness can be Removed by:
Adding Washing Soda:
-Added carbonate ions react with Ca² and Mg² ions to form an insoluble precipitate of Calcium carbonate and Magnesium carbonate Getting rid
of the ² ions

Ion Exchange Columns:
-Columns contain sodium/hydrogen ions which are exchanged for the calcium…

Comments

Subash Poudyal

Report

Absolutely fantastic! thanks a lot :)

Similar Chemistry resources:

See all Chemistry resources »See all resources »