Group--- vertical column
Period--- horizontal row
There is a decrease in metallic properties across a period
Same group--- same valency/number of valence electrons
Same period--- same number of shells
Left to right--- gradual change from metals to non-metals
Group I to Group III--- lose electrons to form cations
Group V to Group VII--- gain electrons to form anions
Group IV--- can either gain or lose electrons
The group number determines the number of valance electrons (and thus, valency) of the element while the period determines the number of electron shells in an atom of that element.
Properties:
Trends:
Properties:
Trends:
Properties:
Trends:
1) Increases down the group: Boiling point, mass
Uses:
Helium: for filling balloons and airships
Argon: for filling tungsten bulbs
Neon: used in lights and advertising signs
Xenon: used in vehicle headlamps
Argon: to provide inert atmosphere for processes like welding
Oxygen: welding, oxygen tents and tanks.