The Simplest Matter
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Transcript of The Simplest Matter
The Simplest Matter
The ElementsAn element is matter made of only one kind of atom. There are
110 known elements, and 90
of those occur naturally on
Earth.
Chemists have created a chart called the Periodic Table of the
Elements to help them organize and display the elements.
The Periodic TableThe elements are organized on the
periodic table by their properties. There are
rows and columns that represent
relationships between the elements.
The Periodic Table
The rows in the table are called periods. The elements in a row
have the same number of energy levels.
The Periodic Table
The columns are called groups. The elements in each group have
similar properties related to their structure.
Atomic NumberChemic
al Symbol
Atomic Mass
In the periodic table, each element is
represented by a chemical symbol that
contains one to three letters.
Chemical Symbol
Atomic Numbe
rThe atomic
number tells you the
number of protons in
the nucleus of that
element.
Atomic Mass
The atomic mass is the
average mass of an atom.
Classification of Elements
Elements fall into three general categories – metals, metalloids, and
nonmetals. The elements in each category have similar properties.
MetalsMetals generally have a shiny or
metallic luster and are good conductors of heat and electricity.
All metals except mercury, are solid at room temperature.
Nonmetals
Nonmetals are elements that are usually dull in appearance. Most are poor conductors of heat and electricity. Also, many are gases
at room temperature.
MetalloidsMetalloids are elements that
have characteristics of
metals and nonmetals. All metalloids are solids at room temperature.