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Subatomic Physics: Nuclear Processes IA Very Brief Presentation

Mr. Bean

Physics

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Key terms- What is Radioactivity?

Radioactivity– process by which an unstable nucleus emits one or more particles or energy in the form of electromagnetic radiation

Nuclear radiation- charged particles or energy emitted by an unstable nucleus

Alpha Particle- A positively charged particle, emitted by some radioactive nuclei, that consists of two protons and two neutrons

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Key terms (continued)

Beta Particle- an electron emitted during the radioactive decay of a neutron in an unstable nucleus

Gamma Ray- High- energy electromagnetic radiation emitted by a nucleus during radioactive decay

Neutron Emission – The release of a high-energy neutron by some neutron-rich nuclei during radioactive decay

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Types of radiation: Alpha Particle,

Consist of 2-protons and 2-neutrons Sometimes referred to as He Atomic mass = Atomic # = Charge =

Barely pass through a sheet of paper Most massive type of radiation Ionize matter (remove e-)

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Types of radiation: Beta Particle,

Fast moving electrons Emitted during the radioactive decay of a neutron in a

an unstable nucleus Charge = Goes through paper, but stopped by 3mm of Al or

10mm of wood. Ionize other atoms

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Types of radiation: Gamma rays,

Not made of matter: no mass or charge Form of electromagnetic energy, i.e. light or X-rays Very penetrating: 60 cm of Al or 7 cm of Pb Do not ionize easily, but can cause damage due to its

high energy

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Types of radiation: Neutron radioactivity

Neutron emission consists of matter emitted form an unstable nucleus

No charge and do not cause ionization like or particles

15 cm of Pb is required to stop penetration

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Radioactive decay

Radioactive decay is the spontaneous release of energy in the form of radioactive particles or waves.

This decay results in a decrease over time of the original amount of radioactive material.

ZAX A =

Z =

X =

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Nuclear Decay: - decay

Nucleus gives up two protons and two neutrons

ZAX

88226

86222

24Ra Rn He

89217

24Ac X HeZ

A

89225

87221Ac X FrZ

A

83221

24Bi X HeZ

A

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Nuclear Decay: -particle

Nucleus gains a proton and loses a neutron For convenience, an electron has an atomic # = -1 -particle essentially has no mass (9.11 x 10-31 kg)

512

612B C XZ

A

614

714

10C N e

2863

10Ni X eZ

A

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Energy is released during fission

One mole of trinitrotoluene (TNT) is about 4.8 x 10-18 J of energy

Einstein, E = mc2, m = mass, c = speed of light c = 3.0 x 108 m/s or 186,000 mi/s 1 kg of matter is 9 x 1016 J of energy, which is

more chemical energy than 8 million tons of TNT