this presentation is about nuclear chemistry, It covers neutron-proton ratio and stability band to identify an isotope is stable or radioactive.

1. TOPIC

2. • Very few nuclides exist with N/Z neutron proton ratio less
than 1 (N/Z <1) means no of proton greater than no of
neutron
1H1 and 3He2
(Proton rich elements are unstable except Hydrogen)
For lighter stable nuclides neutron proton ratio is equal to 1
4He2 ,
12C6 ,
16O8 ,
14N7 ,
20Ne10
Only 85% Nuclei are Stable

5. • Just as the noble gases the element
with 2 , 4 , 8 , 10 , 16 , 18 , 20 , 36 ,
40 , 54 and 86 electrons are
exceptionally stable because of their
filled electron shell, nuclides with N/Z
valves of 2 , 4 , 8 , 10 , 16 , 18 , 20 ,
36 , 40 , 54 and 86 are exceptionally
stable as well.

7. • Elements with in Even number of
protons(Z) usually have large number
of stable Nuclides than element with
Odd number of protons(Z).

8. Elements Atomic Numbers No of Stable Nuclides
Cd 48 8
In 49 2
Sn 50 10
Sb 51 2
Te 52 8
I 53 1
Xe 54 9

9. Proton (Z) Neutron (N) No of Nuclides
(STABLE)
Even Even 157
Even Odd 53
Odd Even 50
Odd Odd 07

10. • Most elements have isotopes for stable
isotopes an interesting plot arises when the
number of neutrons is plotted versus the
number of protons.

13. Protons are positively charged and neutrons
are uncharged , but holds the nucleus
together.
As the nucleus get bigger Electrostatic
Repulsion Force between proton would break
the nucleus apart. There is a Strong force
exist between all nucleons.

17. Made By
• MUHAMMAD ARSALAN USMANI
• ALI RAZA SIDDIQUE
• SAAD UL HAQ
• ABDUL HAFEEZ
BS CHEMISTRY 3RD YEAR SEMESTER 6TH