After
reading this section you will be able to do the following:
Define
an atom.
Define
a Basic Element.
All matter, such as solids,
liquids and gases, is composed of atoms. Any material that
is composed of only one type of atom is called a chemical element,
a basic element, or just an element. An atom is the smallest particle
of any element that still retains the characteristics of that
element. A piece of an element that we are able to see or handle is made of many, many atoms and all atoms are the same...they all have the same number of protons. Protons and other subatomic particles will be discussed a little later. The atoms of different elements are different
from each other because they have different numbers of protons. The graphic below illustrates this point by showing
the atoms of two elements in the containers of oxygen and hydrogen.
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The atoms in oxygen are
identical to each other. The atoms in hydrogen are identical to
each other. However, the atoms of oxygen are different from the
atoms of hydrogen.
Compounds, like water, are
formed by combining the atoms of different elements together according
to some chemical formula.
Review:
An atom
is the smallest particle of an element that remain identical
to all other particles.
The atoms
of one element are different from those of all other element.
Compounds
are made when atoms of different elements are chemically combined
together.
