Decay

There are 3 types of radioactivity

• Alpha

• Beta

• Gamma

Alpha Radioactivity

Alpha radioactivity is a form of nuclear decay that produces a transmution. A transmutation occurs when an element 's nucleus changes and it becomes a different element.

Nuclear Decay

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Open Ended

What is a transmutation?

Alpha Radioactivity

This type of transmutation causes the nucleus of an atom to emit an alpha particle composed of 2 protons and 2 neutrons, and energy.

This will change the atomic mass, because the atom is losing 2 protons and 2 neutrons. The mass will decrease by 4 amu's.

Multiple Choice

If an atom of plutonium, with a mass number of 244 and 94 protons undergoes alpha decay, what will its mass number be?

• 244

• 240

• 248

• 94

Since the atom that undergoes alpha decay loses 2 protons, it's atomic number, and therefore its name, will also change.

Multiple Choice

If an atom of plutonium, with an atomic number of 94 and a mass of 244 emits an alpha particle, what will it become?

• It will be plutonium but its atomic number will be 92

• It will have 94 protons and 134 neutrons

• Plutonium without any radioactivity

• It will become a uranium atom with a mass of 240 amu's and 92 protons.

Alpha Particles

Alpha particles are slow moving and can be stopped by clothing or a piece of paper. They can only travel a few centimeters through the air. If course, if you eat or inhale a bunch of alpha particles, you will get sick or die.

Alpha Particles

Alpha particles have 2 protons and 2 neutrons, but no electrons.

Multiple Choice

An alpha particle has 2 protons, 2 neutrons and no electrons, so what will it's charge be?

• +1

• +2

• -1

• -2

Multiple Choice

Use your periodic table to determine what kind of atom has 2 protons and 2 neutrons.

• helium

• hydrogen

• beryllium

• lithium

Beta Decay

When an atom undergoes beta decay, a proton changes into a neutron and emits a fast moving electron out of the nucleus. This, like alpha decay, causes a transmutation.

Beta Decay

With beta decay, a neutron changes into a proton, but that doesn't change the mass, since it has the same number of protons plus neutrons. However, it DOES change the number of protons, so the atomic number and the name of the atom changes.

Multiple Choice

Uranium, atomic number 92, has a mass of 238. If it undergoes beta decay, what will its mass number be?

• 238

• 242

• 234

• 236

Multiple Choice

Uranium, atomic number 92, has a mass of 238. If it undergoes beta decay, what will its atomic number and name be?

• Thorium, atomic number 90

• Neptunium, atomic number 93

• radium, atomic number 88

• plutonium, atomic number 94

Beta Radiation

A Beta particle, the electron that is emitted from the nucleus, can travel farther and faster than alpha particles, but they can be stopped by a layer of aluminum foil

Gamma Radiation

Gamma is a type of radioactivity that does not cause a transmutation. There are no particles produced, only large amounts of high energy electromagnetic waves.

Gamma Radiation

Gamma waves can pass through matter easily. It can be stopped only by thick slabs of lead or concrete. Because of this, it is the most dangerous kind of radioactivity.

Multiple Choice

Which type of radioactivity is a product of the nucleus of an atom?

• Alpha

• Beta

• Gamma

• All radioactivity comes from the nucleus

Multiple Choice

Which type of radioactivity does NOT cause a transmutation?

• Alpha

• Gamma

• Beta

• All types of radioactivity cause the atom to transmute into another type of atom

Multiple Choice

Which type of radiation is the least dangerous?

• Alpha

• Beta

• Gamma

• Delta

Multiple Choice

Which type of radioactivity produces a helium atom with a positive charge?

• alpha

• beta

• gamma

• all of them