well use it

1. Nuclear Stability

2. What is the nuclear
stability?

3.  Nuclear stability means that nucleus is stable
meaning that it does not spontaneously emit
any kind of radioactivity (radiation).

4. Nuclear Stability Graph
The nucleus holds the neutrons and protons
by the forces which counter balances each
other.
In the diagram shown below, the red line
depicts the stable nuclei and green line
depicts the nuclei with the equal number
of neutron and protons.

5. if the nucleus is unstable
(not stable), it has the
tendency of emitting some
kind of radiation, i.e., it is
radioactive.
Radioactive

6. Stable nucleus – non-radioactive
Unstable nucleus – radioactive
 Keep in mind that less stable
means more radioactive and more
stable means less radioactive.

7. We want to know why there is a
radioactivity.
 What makes the nucleus a stable one?

8. There are no concrete theories to explain
this, but there are only general observations
based on the available stable isotopes.

9. How do we predict the nuclear
stability?

10. One of the simplest ways of predicting
the nuclear stability is based on nucleus
contains odd/even number of protons
and neutrons:

11. Protons Neutrons Stability
Odd Odd least stable
 Nuclides containing odd numbers of
both protons and neutrons are the
least stable means more radioactive.

12. Protons Neutrons
Odd Even
Nuclides contain odd numbers of
protons and even numbers of neutrons
are less stable than nuclides containing
even numbers of protons and odd
numbers of neutrons.

13. Protons Neutrons Stability
Even Even most stable
Nuclides containing even numbers of
both protons and neutrons are most
stable means less radioactive.

14. In general, nuclear stability is greater
for nuclides containing even numbers
of protons and neutrons or both.

15. Examples to
solve:

16. Based on the even-odd rule ,
predict which one would you
expect to be radioactive in each
pair?

17. Solve it;
 (a) 168O and 178O

18. Solve it;
(b) 3517Cl and 3617Cl

19. Answer for (b) ;
(b) The 3517Cl has 17 protons and 18
neutrons (odd-even) and the 3617Cl has
17 protons and 19 neutrons (odd-odd).
Hence, 3617Cl is radioactive.

20. Solve it;
(c) 2010Ne and 1710Ne

21. Answer for (c) ;
 (c) The 2010Ne contains 10 protons and
10 neutrons (even-even) and the
1710Ne contains 10 protons and 7
neutrons (even-odd). Therefore, 1710Ne
is radioactive.

22. Solve it;
(d) 4020Ca and
4520Ca

23. Answer for (d) ;
 (d) The 4020Ca has even-even situation and
4520Ca has even-odd situation. Thus,
4520Ca is radioactive.