The chemical behavior of any element is determined by the number,
and configuration of its electrons.
Mendeleev found that
when the elements are arranged in order by their atomic number, the resulting pattern
of chemical properties suggests that the outer most "shell" (a.k.a. energy level, orbital,
valence shell) is 'filled' by 8 electrons as 4 paired electrons. He called this the
Periodic Table of the Elements.
| Periodic Table of the elements | |||||||||||||||||
| i | ii | iii | iv | v | vi | vii | viii | ||||||||||
| H | He | ||||||||||||||||
| Li | Be | B | C | N | O | F | Ne | ||||||||||
| Na | Mg | Al | Si | P | S | Cl | Ar | ||||||||||
| K | Ca | Sc | Ti | V | Cr | Mn | Fe | Co | Ni | Cu | Zn | Ga | Ge | As | Se | Br | Kr |
| Rb | Sr | Y | Zr | Nb | Mo | Tc | Ru | Rh | Pd | Ag | Cd | In | Sn | Sb | Te | I | Xe |
| Cs | Ba | La* | Hf | Ta | W | Re | Os | Ir | Pt | Au | Hg | Tl | Pb | Bi | Po | At | Rn |
| Fr | Ra | Ac* | Rf | Ha | |||||||||||||
| *Ce | Pr | Nd | Pm | Sm | Eu | Gd | Tb | Dy | Ho | Er | Tm | Yb | Lu | ||||
| *Th | Pa | U | Np | Pu | Am | Cm | Bk | Cf | Es | Fm | Md | No | Lr | ||||
Most Periodic Tables now include additional information [for example Carbon]:
| atomic mass | symbol | charge |
| atomic number | number of atoms |
for example Carbon:
| 12 | C | 0 |
| 6 | 1 |
Valence electrons
| Chemical Bonds | ||
| covalent | . | strongest |
| polar covalent | . | . |
| ionic | . | . |
| hydrogen | . | weakest |
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© 2004-2005 TwoOldGuys ™
revised 19 aug 2006