The Periodic Table of Elements

First off, you may want to open this free printable periodic table so that you can the groups and families.

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.

• Column I A- Alkali Metals
• Column II A- Alkaline Earths
• Columns III B through I B - Tranistion elements
• Column VII A - Halogens
• Column 0 - Noble Gases

Periods
The horizontal rows of the periodic table are called periods. Elements in a period are not alike in properties but rather, in mass. 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.

Understanding the Box
For the following paragraphs you can refer the to the image above with the HE in the middle. 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.

Atomic Number
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.

Symbol
The large letter(s) 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 usually useful to memorize symbols and names for elements, at least for the more commonly used elements. There's a video below that can help you remember the names of the elements.

Atomic Mass
Below the name is the element's atomic mass. The average mass of one atom of that element in amu's (Atomic Mass Units). It is average because different isotopes of the same element have different masses.