The Periodic Table lists elements in ascending atomic number.
is a material or substance made from atoms
that have the same atomic number. For example oxygen
is an element
that is composed of oxygen atoms
with eight protons
Elements may undergo chemical reactions with other elements or compounds to form new compounds. There are more than 110 known elements, with new ones still being discovered - this is because some elements are very unstable and cannot exist except under special conditions (the heaviest stable element
is uranium). These unstable transuranic elements can be created by colliding heavy nuclei together.
The elements are most commonly arranged in ascending atomic number (Z) order in the Periodic Table.