periodic table

1. Presentation outline
1)Modern periodic table
2)Group
3)Period
4)Reactivity in periods
5) Reactivity in groups
6) Reactivity in metals
7) Reactivity in non metals.

2. Modern periodic table

4. Periods
 Modern periodic table consists 7 horizontal
rows called periods
 First period has two elements H and He called
very short periods
 Second period has 8 elements Li to Ne called
short period
 Third period has 8 elements Na to Ar short
period

5.  Rb to XE called long period
 Cs to Rn called very long period
 From 58 to 71 called lanthanides
 The lanthanide series is the group of elements in
which the 4f sub shell is being filled. All of them
are metals (transition metal)
 From 90 to 103 called actinides
 Actinides are all radioactive elements. There 5f
sub shell is being filled

6. Groups

7. Reactivity in Periods
 The reactivity decrease on moving from left to
right in period IA to IVA due to increase in
valency
Eg in period 2 Li is more reactive than Be because
it is easier to remove single electron of Li than two
electron of Be
 But reactivity increases on moving from left to
right in a period VI to VIIA
 Eg in period 3 Cl is more reactive than P and S
because decrease in valency it is easier to gain
or loss one electron(Cl) than two electron(S)

8. Reactivity on groups
 In case of metal , while moving from top to
bottom reactivity increases due to large size can
easily loose electron
 In non metal reactivity decrease due to small
atoms can gain electron easily than large atoms
 If question is one metal and one non metal first
see the valency , whose valency is less it is
more reactive .
 If valency is same , the electronegetive(gain)
elements is more reactive.

9.  Group IA (H-Fr) and II(Be-Ra) are metals
 Group IIIA(B), IVA(C, Si), VA(N,
P,As) and VIA(O, S, Se) are non
metals which are placed at right side
on zig zag.
 Metalloids are placed in between
metals and non metals
They are B, Si, Ge, As, Sb, Te and po
 Group VIA are called chalcogens
 Group VIIA or 17 are called halogens
 Group 18 are called inert or noble
gas