There are 118 known elements on the periodic table. The most recently discovered element, Ununoctium, was first reported by Russian scientists from Dubna in 2002. More »

The element nitrogen belongs to the nitrogen family, which is situated in the p-block in group 15 on the periodic table of elements. The elements arsenic, bismuth, antimony and phosphorus also belong to the same group be... More »

You can memorize the periodic table by breaking it down into different groups and learning one section at a time. Practice by filling in blank tables, or create a song using the elements' symbols. More » Education Homework Help Study Skills

The periodic table was built to show the relationships among the various elements. The periodic table was constructed in 1869 by Dmitri Mendeleev. More »

Some elements on the periodic table are oxygen, helium, arsenic and fluorine. Oxygen is an odorless, tasteless and colorless gas at room temperature, but is bright blue as a liquid. Oxygen is a very reactive element and ... More » Science Chemistry

The periodic table was invented by chemist Dmitri Mendeleev to organize and compare elements and understand their relations with each other. Mendeleev created the periodic table between 1868 and 1870 while writing his bo... More »

The horizontal rows on the periodic table of the elements are called periods. Every element in a period has the same number of atomic orbitals. For instance, hydrogen and helium are in the first period, so they both have... More »