it depends which version you are referring to. there is more than one variation.
Ununoctium was discovered (prepared) in 2006; old Mendeleev tables (printed before 2006) don't contain ununoctium.
Hydrogen.
Go to this website
he made up the periodic tables
Dmitri Mendeleev.
no, they depend on what country your in
The columns are known as groups.
Periodic tables are important in most scientific classes because they help understand similarity of properties and reactions of elements.
7The Periodic Table has 7 periods and 18 groups.
There have been around 700 different periodic tables created since the concept was first introduced in the 19th century. These periodic tables vary in organization, structure, and focus, but all aim to arrange the elements based on their properties and behaviors.
Jeff And BoB
Periodic Tables. lol. Also, tables on old navy ships had no legs. The table was attached to strings on the ceiling so that as the ship moved and bobbed, the table would always stay upright because of gravity and the food wouldn't slide off.