1. Isobaric transitions Alpha emission TRANSFORMATION MECHANISMS Isomeric transitions Orbital electron capture Positron emission Beta emission Internal conversion Gamma ray emission

2. Alpha emission: All nuclei with more than 83p decay spontaneously It may also decay (beta decay) Stable! Unstable!

3. Alpha emission

4. ( ) 1) Beta emission Unstable! We will se later! 2) Positron emission Unstable! Stable 3) Orbital electron capture Unstable! Stable * Isobaric transitions :

5. - Beta emission - - - - - - - - Proton + electron - neutron o + + + - - - - - - - - + + + +

6. Positron emission - - - - - - - - neutron o electron + proton + + + + + + - - - - - - - - + + + +

7. Orbital electron capture neutron o electron - proton + + + + + + + + + +

9. Beta emission p + n o e + n o p + e - n o p + e - n o p + e - p + n o e + n o p + e - Beta

10. Positron emission p + n o e + n o p + e - p + n o e + p + n o e + p + n o e + n o p + e - Positron

11. p + n o e + n o p + e - p + n o e + p + n o e + n o e - e - e - e -

12. p + n o e + n o p + e - n o D U D p + U U D e -

13. 2) Internal conversion1) Gamma ray emission Isomeric transitions: ( ) * As we saw from the previous slide Carbon 14 turned in to Nitrogen 14, BUT that Nitrogen is not the regular nitrogren it is UNSTABLE NITROGEN! Why?! Because that Nitrogen has a high energy that it should be release * Has very big energy It occurs when an excited nucleus interacts with one of its electrons. Which leads to electron to be ejected from the atom. The electron emitted from that excited atom has a very high energy Therefore, the high-speed electrons resulting from internal conversion are NOT BATE (as is the case with gamma ray)

14. Gamma ray emission Internal conversion high-speed electrons (NOT BATE)

15. TRANSFORMATION MECHANISMS conditionsnote Alpha emission more than 83 protons Isobaric transitions Beta emission(n/p) ABOVE band of stability (too many n) Positron emission(n/p) BELOW band of stability (too many p) Orbital electron capture(n/p) BELOW band of stability (too many p) Isomeric transitions Gamma ray emissionnuclei high energy that it should be release Internal conversion excited nucleus interacts with one of its electrons high-speed electrons (NOT BATE)