The Periodic Table is a well-organized chart that contains all 118 known elements in the universe. These elements are the ...

The periodic table of chemical elements, often called the periodic table, organizes all discovered chemical elements in rows (called periods) and columns (called groups) according to increasing atomic ...

Atomic structure - AQA Atoms consist of a nucleus containing protons and neutrons, surrounded by electrons in shells. The number of subatomic particles in an atom can be calculated from the atom's ...

The numbers of subatomic particles in an atom can be calculated from its atomic number and mass number. The periodic table - AQA Mendeleev made an early periodic table. In the modern periodic ...

This story appears in the May 2013 issue of National Geographic magazine. N. Nitrogen. Atomic number seven. Unnoticed, untasted, it nevertheless fills our stomachs. It is the engine of agriculture ...