© Copyright Pearson Prentice Hall Slide 1 of 21 Nuclear Radiation Marie Curie was a Polish scientist whose research led to many discoveries about radiation

© Copyright Pearson Prentice Hall

Slide 1 of 21

Nuclear Radiation

Marie Curie was a Polish scientist whose research led to many discoveries about radiation and radioactive elements. In 1934 she died from leukemia caused by her long-term exposure to radiation. You will learn about the various types of radiation and their effects.

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Nuclear Radiation >

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Radioactivity

Radioactivity

How does an unstable nucleus release energy?

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Nuclear Radiation > Radioactivity

Marie Curie (1867-1934) and Pierre Curie (1859-1906) were able to show that rays emitted by uranium atoms caused fogging in photographic plates.

• Marie Curie named the process by which materials give off such rays radioactivity.

• The penetrating rays and particles emitted by a radioactive source are called radiation.

-They discovered several radioactive isotopes.

*reason that Dalton’s indivisible atom idea was changed

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Nuclear reactions differ from chemical reactions in a number of important ways.

• In chemical reactions, atoms tend to attain stable electron configurations by losing or sharing electrons.

• In nuclear reactions, the nuclei of unstable isotopes, called radioisotopes, gain stability by undergoing changes, and are ALWAYS accompanied by emission of large amounts of energy.

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An unstable nucleus releases energy by emitting radiation during the process of radioactive decay.

•An unstable nucleus is something that is considered to have either too few neutrons or too many neutrons relative to the number of protons.

•Eventually unstable radioisotopes transform into stable isotopes of a different element.

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Types of Radiation

Types of Radiation

What are the three main types of nuclear radiation?

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Nuclear Radiation > Types of Radiation

The three main types of nuclear radiation are alpha radiation, beta radiation, and gamma radiation.

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Alpha Radiation

Alpha radiation consists of helium nuclei that have been emitted from a radioactive source. These emitted particles, called alpha particles, (α) contain two protons and two neutrons and have a double positive charge.

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Beta Radiation

An electron resulting from the breaking apart of a neutron in an atom is called a beta particle. (β)

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Carbon-14 emits a beta particle as it undergoes radioactive decay to form nitrogen-14.

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Gamma Radiation

A high-energy photon emitted by a radioisotope is called a gamma ray. (ϒ) The high-energy photons are electromagnetic radiation.

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Alpha particles are the least penetrating. Gamma rays are the most penetrating.

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Section Quiz

-or-Continue to: Launch:

Assess students’ understanding of the concepts in Section

25.1 Section Quiz.

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25.1 Section Quiz.

1. Certain elements are radioactive because their atoms have

a. more neutrons than electrons.

b. an unstable nucleus.

c. a large nucleus.

d. more neutrons than protons.


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25.1 Section Quiz.

2. An unstable nucleus releases energy by

a. emitting radiation.

b. thermal vibrations.

c. a chemical reaction.

d. giving off heat.


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25.1 Section Quiz.

3. Which property does NOT describe an alpha particle?

a. 2+ charge

b. a relatively large mass

c. a negative charge

d. low penetrating power


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25.1 Section Quiz.

4. When a radioactive nucleus releases a high-speed electron, the process can be described as

a. oxidation.

b. alpha emission.

c. beta emission.

d. gamma radiation.


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25.1 Section Quiz.

3. Which property does NOT describe an alpha particle?

a. 2+ charge

b. a relatively large mass

c. a negative charge

d. low penetrating power

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© Copyright Pearson Prentice Hall Slide 1 of 21 Nuclear Radiation Marie Curie was a Polish scientist whose research led to many discoveries about radiation