Atomic Size
Measured in
Picometers
Non-metals are: Electropositive/electronegative
Electronegative
Oxides of metals are
Basic in Nature
How to determine chemical reactivity
Number of valence electrons
Valency of group 15 elements
3
Variation along a period
Size of atoms decreases from left to right
Position of electronegative elements in the periodic table
The right-hand side of the Periodic Table towards the top
True or False: There is no change in the nature of oxides as we go down in a group
True
Variation along period
First increases then decreases
Variation along a group
Elements in a group have the same valency
Which has the largest atomic size: sodium, magnesium or aluminium
Sodium
Metallic character (or electropositivity) down the group
Increases
Nature of oxides of Fluorine, Bromine, Chlorine
Acidic
Why is helium unreactive
Has completely filled valence shell
Valency of Li, Na and K
1
Variation along a group
Increases down the group
What do these trends help us to predict the nature of?
Oxides formed by elements
Nature of Oxide Aluminium
Amphoteric
Reactivity of metals along the group
Increases on going down
Calcium has the same valency as Boron, Barium or Fluorine
Barium
Which has the largest atomic size: Beryllium, Magnesium, Calcium
Calcium
The most electropositive element among Carbon, Chlorine, Potassium and Calcium
Potassium
Most acidic oxide in the 2nd period
Fluorine oxide
Most reactive group
Alkali metals and Halogens
Group of elements with filled outermost shell
Group 18- Nobles Gases