WATER (H 2 O)

substance naturally present on the earth in all states. Cover about

75% of the earth surface. Oceans help in the balance of the world. Essential for all living organisms. Makes up 60% of trees, 70% of the body of an elephant,95% of a tomato, 70% of the human body and 90% of our blood. Needed to dissolve chemicals in our cells and to carry chemicals in our body.

+ ½ O2
electrolyze

and freezes at 0 0C. (at STP) Density is the highest

at 40C, 1 g/cm3 . Having the lower density when it freezes makes life possible in seas and lakes.

O2
electrolyze

nuclear power plants. Production of steel and paper. In the home for

cooking, drinking and washing. Water steam is used to generate electricity. To extract minerals and to manufacture of several chemicals.