Module Outline - hdbk11300052

DOE-HDBK-1130-98

Module 1: Radiological Fundamentals

Instructor's Notes

II.

MODULE OUTLINE

Atomic Structure

The basic unit of matter is the atom. The three basic particles

of the atom are protons, neutrons, and electrons. The central

portion of the atom is the nucleus. The nucleus consists of

protons and neutrons. Electrons orbit the nucleus.

EO1 Identify the three basic

particles of an atom.

Protons

1) Protons are located in the nucleus of the atom.

2) Protons have a positive electrical charge.

3) The number of protons in the nucleus determines the element.

(Optional)

Insert diagram of the atom.

Have students label the

three basic particles.

Neutrons

1) Neutrons are located in the nucleus of the atom.

2) Neutrons have no electrical charge.

3) Atoms of the same element have the same number of protons,

but can have a different number of neutrons.

4) Atoms which have the same number of protons but different

numbers of neutrons are called isotopes.

NOTE: Common notation for describing isotopes is to list the

atomic symbol for an element followed by its mass number. The

mass number is the sum of protons and neutrons. For example,

tritium has 1 proton and 2 neutrons, and is denoted as H-3.

5) Isotopes have the same chemical properties; however, the

nuclear properties can be quite different.