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BASIC ATOMIC STRUCTURE FACT SHEET
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The normal atom (also called a stable atom) has three main parts (or particles) that we are concerned
with; protons, neutrons, and electrons.
A fourth part, the nucleus, is often referred to but we are not focusing on it as much as we are on
protons, neutrons, and electrons. The nucleus is the central part of the atom.
Protons and neutrons are located in the nucleus or central part of an atom.
Electrons constantly orbit around the nucleus.
Protons have a positive charge. The number of protons that an atom has is its atomic number.
Neutrons do not have a charge, therefore they are said to be neutral.
Electrons have a negative charge. The number of electrons that a normal (or stable) atom has is
equal to the number of protons that it has.
Therefore the number of protons, the atomic number, and the number of electrons in a normal (or
stable) atom are all the same number.
An atom is held together by the electromagnetic attraction between the positive protons and
negative neutrons. Opposites attract…..likeness repel.
BASIC INFORMATION FROM A PERIODIC TABLE
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A periodic table is a chart of the elements arranged primarily according to the element’s atomic
number.
An element is a pure substance composed of identical atoms.
The above diagram is of what the element carbon looks like on a periodic table.
The atomic number is the number of protons that a single atom of carbon contains.
The element name is self-explanatory….the name of the element.
The symbol is a short notation (all symbols are 1 or 2 letters) for the element.
The atomic mass is the combined number (or weight) of all the protons and neutrons in a single
atom of the element. In the above diagram the atomic mass is the combined weight of all the protons
and neutrons in a single atom of carbon.
THEREFORE, the atomic mass (the combined number or weight of all the protons and neutrons
in a single atom) minus the atomic number (the number of protons in the atom) equals the
number of neutrons in the atom.