Dmitri Mendeleev
Russian chemist
2.5 The Periodic Table - Dimitri Mendeleev (1869) published a table with the 63 known elements arranged according to increasing atomic mass. Mendeleev had a couple of "gaps" in his table and predicted that these elements would have properties similar to other elements in "their group" - this is known as the periodic law. A "period" is a row in the table . . . . a group (or family) is a column.
There are three main element groupings:
- Metals - shiny, . . . can be hammered, pressed or bent without cracking or breaking., good conductors of heat and electricity
- Nonmetals - dull, poor conductors of heat and electricity
- Metalloids - conduct heat and electricity moderately well
Other element groupings are:
- Representative elements (Columns 1, 2, 13-18)
- Transition metals (Columns 3-12)
- Inner Transition metals (two rows at the bottom)
- Alkali metals (Column 1)
- Alkaline metals (Column 2)
- Halogens (Column 17)
- Noble gases or Inert gases (Column 18)
Click the image above to launch a website where you can spell your name or a favorite phrase with element symbols.
The Periodic Table.
just elements of it.
if you can't Curium,
pray to the Sun god to Helium.
If that fails, Barium.
He's a little LiAr.
For a page full of "Elemental PuNS", click Pu N S
Several decades after Mendeleev published his Periodic Table, it became apparent that the Periodic Table should be arranged according to atomic number rather than atomic masses (a couple of elements switched places). With this change, the periodic law now states that the . . . flammability, reactivity, toxicity, etc. and . . . color, density, hardness, melting / boiling points, etc. properties of the elements are periodic functions of their atomic numbers.
- The Group 1 elements Sodium and Lithium have similar chemical and physical properties.
- The Group 17 elements Fluorine and Chlorine have similar chemical and physical properties.
