Oxygen

Oxygen ("O")is another element common on earth with alot of interesting chemistry and extensive organic uses, when things "burn" they are normally just "oxidzing", which is grabbing on to oxygen and releasing a little extra energy in the proccess.

Oxygen is quite common on earth, partly because it is 1/3rd of all water in the world, but it is also about 20% of the atmosphere. Oxygen is critical to human life because we use it to "oxidize"(see above)fats and sugars in out bodies, and we end up with the extra energy that comes out of this reaction.

Liquid oxygen is first of all extremely cold, but also shows a nice light blue color, and oddly enough, sticks to a magnet.

Oxygen is also diatomic, meaning if pure oxygen is left alone, it will bond with itself to form O2, however under some circumstances it will form O3, which is known as ozone, and is quite important because it blocks dangerously powerful ultraviolet light from the sun(thus a hole in the ozone layer would be very bad).

These are my samples!