Periodic Table Facts

• increasing atomic number


  ordered arrangement of all chemical elements
• periodic law


  describes a recurring pattern in which elements in the same column (group) have comparable properties, is present when the chemical elements are grouped in this way
• columns (group)

  help to distinguish in the periodic table
• rows (series / periods)

  An element's period number is the highest unexcited energy level for an electron of that element.
• atomic number = number of protons in an atom
• The first periodic table was produced by Russian chemist Dmitri Mendeleev. It was arranges elements according to their rising atomic weight
• The periodic table is controlled by the international union of pure and applied chemistry (IUPAC)
• • The first element to be created artificially was technetium (Tc). In 1937, it was first synthesized.
• Which superhero is your favourite? Thor, the Nordic god of thunder, is the name of the element thorium (Th).
• 1. There are about 94 elements on the periodic table that occur in nature. All of the other elements are strictly human-made. Some sources state more elements occur naturally because heavy elements may transition between elements as they undergo radioactive decay.
• 1. Most of the elements on the periodic table are metals. The alkali metals, alkaline earths, basic metals, transition metals, lanthanides, and actinides all are groups of metals.
• Changing number of electrons produces ions while changing the number of neutrons produces isotopes.
• The element's atomic mass in atomic mass units is a weighted average mass of the element's isotopes.
• Atomic Radius (half the distance between the center of two atoms just touching each other)

  • increases moving top to bottom down the table
  • decreases moving left to right across the table
• Ionization Energy (energy required to remove an electron from the atom)

  • decreases moving top to bottom
  • increases moving left to right
• Electronegativity (measure of ability to form a chemical bond)

  • decreases moving top to bottom
  • increases moving left to right