Periodic Table of Elements
Valence
Electrons:
1e-
2e-
3e-
Alkali Metals
Other Metals
Alkaline Earth Metals
Other Nonmetals
Transition Metals
Noble gases
Lanthanide Series
Halogens
Actinide Series
Unknown
Ds
Period = ___________
Group = ___________
Rg
Cn
Uut
4e-
5e-
6e-
7e-
115
116
117
118
Uus
Uuo
Uuq Uup Uuh
8e(He = 2e-)
Periodic Table of Elements
Alkali Metals
Actinide Series
Alkaline Earth Metals
Poor Metals
Transition Metals
Nonmetals
Lanthanide Series
Noble gases
Groups or Families
The vertical columns of the periodic table (there are 18) are called groups or families. Elements in the same group or family have similar but not
identical characteristics. You will learn more about the 18 groups in a later section. You can know properties of a certain element by knowing which
group it belongs to.
Periods
The horizontal rows of the periodic table are called periods. Elements in a period are not alike in properties. As a rule, the first element in a period is
usually an active solid, and the last element in a period is always an inactive gas. Atomic size decreases from left to right across a period, but atomic
mass increases from left to right across a period. Atoms on the left of the period, therefore, are usually larger and more lightweight than the smaller,
heavier atoms on the right of the period.
Thinking Inside the Box
When you look at the periodic table, you should notice that each box represents a different element, and each box contains vital information about the
element, including its name, symbol, atomic number, and atomic mass. Look at the sample box below for a description of each of these pieces of
information.
6
C
Carbon
12.011
The top number is the atomic number. Every element has its own unique atomic number. The atomic number tells how many protons are in one
atom of that element. Since no two elements have the same atomic number, no two elements have the same number of protons.
The large letter is the element's symbol, and just below that is the element's name. Each element has its own unique symbol and name. It is often
very useful to memorize symbols and names for elements, especially the more commonly used elements.
Below the name is the element's atomic mass. The atomic mass is the mass in atomic mass units for all possible isotopes of that element. The atomic
mass essentially gives you an estimate of how massive one atom of that element is. (If you round this number, and subtract the number of protons,
you will find the number of neutrons in the element. The number of electrons will be the same as the number of protons.)
From: http://web.buddyproject.org/web017/web017/pertab.html