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Unstable Nuclei and Radioactive Decay

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Presentation on theme: "Unstable Nuclei and Radioactive Decay"— Presentation transcript:

1 Unstable Nuclei and Radioactive Decay
Section 4.4 Unstable Nuclei and Radioactive Decay

2 Objectives Explain relationship between unstable nuclei and radioactive decay Characterize alpha, beta, and gamma radiation in terms of mass and change

3 Review Recall chemical reactions Are new substances formed?
Were atoms affected/changed? Chemical reactions only involve electrons Nucleus is NOT affected in CHEMICAL REACTIONS

4 Nuclear Reactions DO change the nucleus
Atoms of one element change into atoms of another

5 Radioactivity Substance spontaneously emits radiation
Rays and particles are called radiation Atoms change into other elements

6 Unstable Systems Radioactivity occurs when an atom’s nucleus is unstable Unstable systems gain stability by losing energy

7 Radioactive Decay Unstable nucleus loses energy by emitting radiation spontaneously Radiates until stable New atom forms

8 Types of Radiation Alpha Beta Gamma

9 Alpha Radiation Deflects toward a negative charge Alpha particles
2 protons & 2 neutrons 42He or  Blocked by only a thin sheet of paper

10 Nuclear Equation 22688 Ra  Rn He Radium Radon

11 Beta Radiation Deflect toward positive charge Beta particles, 
Electron (-1 charge) Aluminum blocks beta radiation 146C  147N 

12 Gamma Radiation High energy radiation No mass No charge Most dangerous
Accompany  or  particles Account for energy lost CANNOT form new atom on its own 00

13 Characteristics of Radiation Types
Symbol Mass (amu) Charge Alpha 4 2+ Beta 1/1840 1- Gamma




17 Practice 6027Co  6028Ni + ____ 24195Am  ____ + 42He

18 Practice Solution 6027Co  6028Ni + 0-1 24195Am  23793Np + 42He
Complete the following nuclear reactions: 6027Co  6028Ni + 0-1 24195Am  Np + 42He

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