ChemTime Clock

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 In the Chem Time clock, the numbers have been replaced by the symbols of the corresponding element.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.