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Periodic table of element - Coggle Diagram
Periodic table of element
Trends in
The periodic table
Elements belonging to same group therefore have similar chemical properties
The period number tell us about the number of shells in the electronic structure of an element.
Properties across a period
metalloids
The elements next to the line.
metals
The elements to its left.
non-metals
The elements to its right.
Properties down a group
A whole shell is added to the next atom at the next atom at each step.So the atoms increase in size down a group.The elements also became increasingly metallic
History of periodic table of element
1864's
John Newlands put forward the 'Law of Octaves'.He realised that the properties of every eighth element are repeated.
1869's
Dmitri Mendeleev laid the foundation for the periodic table as we know today.
1829's
Johann Dobereiner fromed groups of similar elements called "triads".
1913's
He was the first person to use atomic number rather than atomic weight to arrange elements in the periodic table.
1803's
John Dalton arrangeed the know elements in order to their relative atomic weight.
Group 0 : The noble gas
Properties
Physical
The lowest boiling points
no colour or smell
The lowest melting points
Chemical
All noble gases have eight valence electrons.(Helium has only two.) They do not react with other elements.
uses of / Benefits
Neon is use in bright lights for signbords.
Helium and Argon are used in welding to protect the metal from being oxidised.
Radition of Radon are used to treat cancer.
elements
Argon
Xenon
Neon
Redon
Helium
what is periodic table of element ?
Classified
Groups
Vertical columns of elements are called group. There are eight groups numbered I to VIII.Group VIII is also know as Group 0.
Example
In Group II,beryllium (period 2) has two shells of electrons.
Magnesium (period 3) has three shells of electrons.
Transition Elements
There is a block of elements between Group II and Group III.These are the transition elements. All the elements in this block are metals.
Period
Horizontal rows of elements are called periods.There are seven periods numbered 1 to 7.When the elements in a period are read from left to right.
Example
In the third period,the elements Sodium,Magnesium and Aluminium have proton numbers 11,12 and 13
Meaning
Periodic table is a table that lists all the elements that are known to us in increasing order of their proton number.
Group I : Alkali metals
elements
Sodium
lithium
Potassium
Rubidium
Caesium
Francium
Properties
Physical
low melting points
low boiling points
Densities are low.
soft and silvery
Chemical
Alkali metals are highly reactive.They react readily with air to fromoxides and with water to from hydroxides.
Group VII : The Hallogens
meaning
The world 'halogen' comes from words that mean generating salt
elements
Fluorine
Chlorine
Bromine
Iodine
Astatine
properties
Physical
very low melting points
very low boiling points
They have characteristic colours
Chemical
The halogens are the most reactive non-metal.They have seven electrons in the outermost shell.Hallogens gain one electrons to from halide ions with a single negative charge.They react with metals to from salt.