in periodic table what is meant by IA, IB,IIA...etc?

Answer 1

They reference the 'columns' in the table. Elements in the same column have similar chemical properties owing to the same number of electrons in their outermost shells being available fo bonding.


Doug

Answer 2

" * A group, also known as a family, is a vertical column in the periodic table of the elements.

Groups are considered the most important method of classifying the elements. In some groups, the elements have very similar properties and exhibit a clear trend in properties down the group — these groups tend to be given trivial (non-scientific) names, e.g. the alkali metals, alkaline earth metals, halogens and noble gases. Some other groups in the periodic table display fewer similarities and/or vertical trends (for example Groups 14 and 15), and these have no trivial names and are referred to simply by their group numbers. Modern quantum mechanical theories of atomic structure explain group trends by proposing that elements within the same group have the same electron configurations in their valence shell, which is the most important factor in accounting for their similar properties."

This, and more, on the periodic table, from Wikipedia, the free, online encyclopedia at:
http://en.wikipedia.org/wiki/Periodic_table

Hope this helps!

Answer 3

This is refrenced to how many valence electrons are in each atom of that gropu... suhc as group VIIA...this means that all the elements under that group have seven valence electrons or they have seven electrons in their highest energy level.