1. 1. Nucleons. Protons and neutrons 2. Nuclide
1. Nucleons Protons and neutrons 2. Nuclide A atom in nuclear chemistry. Identified by the number of protons and neutrons -mass number.

2. 3. Ways to identify nuclides:Ra 88
b. Radium -228

3. Mass Defect and Nuclear Stability
The difference between the mass of an atom and the sum of the masses of its protons, neutrons and electrons.

4. Example:
Helium-4
2 protons (2 x ) = amu
2 neutrons(2x ) = amu
2 electrons(2x ) = amu
total mass = amu
The measured mass = amu
Mass defect = =.03038amu

5. Nuclear Binding Energy
Convert mass to Kg to match units for energy
Kg X meters(squared) / seconds(squared)
1amu = X Kg
.03038amu = x Kg
E = mc2
E=( x Kg) (3.00 X 10 8m/s)2
E = 4.54 x Kg x m2/s2 = 4.54 x J
Nuclear Binding Energy = 4.54 x J

6. Nuclear binding Energy
The energy released when a nucleus is formed from nucleons. Can also be thought of as the amount of energy needed to break apart a nucleus. Therefore, the nuclear binding energy is a measure of the stability of a nucleus.

7. Binding Energy per Nucleon
The binding energy of the nucleus divided by the number of nucleons it contains

8. Use pages
1. Calculate the nuclear binding energy of a Sulfur–32 atom. The measured atomic mass of Sulfur–32 is amu.
2. Calculate the nuclear binding energy of a Oxygen-16 atom. The measured atomic mass of Oxygen-16 is amu.
3. Calculate the binding energy per nucleon of a Manganese-55 atom. Measured atomic mass is amu.

9. 8. Nucleons and Nuclear Stability
8. Nucleons and Nuclear Stability Band of Stability – stable nuclei clusters over a range of neutron-proton ratios

10. Radioactive Decay Spontaneous disintegration of a nucleus with emission of particles and/or electromagnetic radiation (nuclear radiation) Radioactive Nuclide unstable nucleus

11. Types of Radioactive Decay 1. Alpha particles. a. Helium -4. b
Types of Radioactive Decay 1. Alpha particles a. Helium -4 b. Both number of neutrons and protons must decrease to stabilize.

12. Beta emission- instability in elements above the band of stability occurs because the nucleus has too many neutrons. To decrease the number of neutrons, a neutron can be converted into a proton and an electron. The electron emitted is called a beta particle.

13. Positron emission- elements below the band of stability have too many protons. A proton can be turned into a neutron by emitting a positron – a particle that has the same mass as an electron, but has a positive charge and is emitted from the nucleus during some types of radioactive decay.

14. Nuclides with too many protons undergo a type of radioactive decay called electron capture, an inner orbital electron is captured by the nucleus of its own atom.
Gamma rays- high energy emr waves emitted from a nucleus as it changes from ground state to excited state.