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A Clock with Chemical Elements

If you would like a ChemTime clock to hang on your wall, you can get one from Educational Innovations.

The Chemical Elements

All materials, whether solid, liquid or gas, are made of atoms. Atoms are the smallest bits of matter. Scientists have found over 100 different kinds of atoms. The many different materials we encounter are made from combinations of these atoms. A material in which all atoms are the same kind is called an element. Therefore, there are over 100 different elements.

Each element has been assigned a number, called its atomic number. In the Chem Time clock, the numbers have been replaced by the symbols of the corresponding element.

Atomic Number Symbol Element

1 H hydrogen Hydrogen is the lightest and the most common atom in the universe.
2 He helium Helium was first discovered in the sun, and its name comes from the ancient Greek word for sun.
3 Li lithium Lithium is the lightest metal, so light it floats on water (and it reacts with water, too).
4 Be beryllium Beryllium is a component of the gemstones beryl, emerald, and aquamarine.
5 B boron Boron is found in borax, which is a commonly used water softener in laundry detergents.
6 C carbon Both diamond and graphite are pure carbon, and so are the newly-discovered buckyballs.
7 N nitrogen Nitrogen is the major component of air.
8 O oxygen Oxygen is the second most abundant element on earth (after silicon).
9 F fluorine Fluorine is used in making fluoride toothpaste.
10 Ne neon Neon is a gas that glows red-orange when electricity flows through it in neon signs.
11 Na sodium Sodium is one of the two elements in table salt (the other is chlorine).
12 Mg magnesium Magnesium is a light metal, and its alloys are used in "mag" wheels on sports cars.
13 Al aluminum Aluminum metal reacts with oxygen, but it forms an oxide coating protects it from further reaction.
14 Si silicon Silicon is the most abundant element in the earth's surface; it's used in making electronic semiconductors.
15 P phosphorus Phosphorus is a non-metal and essential in all biological organisms.
16 S sulfur Sulfur is a yellow solid, and its chief industrial compound is sulfuric acid.
17 Cl chlorine Chlorine is a green gas, but dissolved in water it is an effective disinfectant.
18 Ar argon Argon is an unreactive gas, and it is used to fill light bulbs so the hot filament does not burn.
19 K potassium Potassium is a metal that reacts with water, and its compounds are essential to living organisms.
20 Ca calcium Calcium is a metal, and it is an essential component of bones and teeth.
21 Sc scandium Scandium is a very rare element, and so it is quite expensive and has few uses.
22 Ti titanium Titanium is a metal, and titanium dioxide is the white pigment used in most paints.
23 V vanadium Vanadium is a metal that is added to steel to make it stronger and more heat resistant.
24 Cr chromium Chromium is a metal whose compounds come in many colors, which is the reason for the element's name.

The ChemTime clock was featured in a 2011 holiday gift guide from the Chemical Heritage Foundation.

Check out the Chemicool Periodic Table for more information about the elements.

Professor Shakhashiri's article on the element lead can be found by clicking on lead in this periodic table clicking here.

An interesting Flash animation about the elements

A page with many variations on the periodic table

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