"It
is a huge, efficient resource!"
The
periodic table is the most important chemistry
reference there is. It arranges all the known elements in
an informative array. Elements are arranged left to right and top to
bottom in order of increasing atomic number..
This order generally coincides with increasing atomic mass
The
different rows of elements are called periods. The period number of
an element signifies the highest energy level an electron in that element
occupies (in the unexcited state). The number of elements in a
period increases as one traverses down the periodic table because as the
energy level of the atom increases, the number of energy sub-levels per
energy level increases.
Using
the data in the table scientists, students, and others that are familiar
with the periodic table can extract information concerning individual
elements. For instance, a scientist can use carbon's
atomic mass mass
to determine how many carbon atoms there are in a 1 kilogram block of
carbon.
People
also gain information from the periodic table by looking at how it is put
together. By examining an element's position on the
periodic table, one can infer the electron configuration. Elements
that lie in the same column on the periodic table (called a
"group") have identical valance
electron configurations and consequently
behave in a similar fashion chemically. For instance, all the
group 18 elements are inert gases. The
periodic table contains an enormous amount
of important
information. People familiar with how the table is put together can
quickly determine a significant amount of information about an element,
even if they have never heard of it. |