Reservoir | Volume/km3 | Volume/% total water |
---|---|---|
oceans | 1400 000 000 | 96 |
ice and snow | 43 000 000 | |
underground water | 15 000 000 | 1.0 |
lakes and rivers | 360 000 | 0.025 |
atmosphere | 15 000 | 0.001 |
plants and animals | 2 000 | 0.000 14 |
total | 1460 000 000* | 100* |
Scientific notation requires the number accompanying the power of ten to be less than 10 but equal to or greater than 1.
Element | % |
---|---|
hydrogen | 63.00 |
oxygen | 25.20 |
carbon | 9.50 |
nitrogen | 1.40 |
calcium | 0.31 |
phosphorus | 0.22 |
potassium | 0.06 |
sulfur | 0.05 |
chlorine | 0.03 |
sodium | 0.03 |
all others | 0.20 |
Element | No. of electrons | No. of protons |
---|---|---|
hydrogen | 1 | 1 |
helium | 2 | 2 |
carbon | 6 | 6 |
nitrogen | 7 | 7 |
oxygen | 8 | 8 |
Element | Usual number of bonds |
---|---|
hydrogen | 1 |
carbon | 4 |
nitrogen | 3 |
oxygen | 2 |
sulfur | 2 |
chlorine | 1 |
Element name | Origin of name | Symbol |
---|---|---|
hydrogen | from the Greek, hydro (water) and genes (forming) | H |
helium | from the Greek, Helios (the Sun) | He |
carbon | from the Latin, carbo (charcoal) | C |
nitrogen | from the Greek, nitron and genes (soda forming) | N |
oxygen | from the Greek, oxys and genes (acid forming) | O |
sodium | from the English, soda (natrium in Latin) | Na |
magnesium | from Magnesia, a district of Thessaly in Greece | Mg |
aluminium | from the Latin, alumen (alum) | Al |
silicon | from the Latin, silex (flint) | Si |
sulfur | from the Latin name sulphur for the element | S |
chlorine | from the Greek, chloros (yellowish green) | Cl |
potassium | from the English, potash (symbol from kalium - Latin for alkali) | K |
calcium | from the Latin, calyx (lime) | Ca |
iron | Anglo-Saxon name for the metal; the Romans called it ferrum | Fe |
bromine | from the Greek, bromos (stench) | Br |
Element | No. of electrons | No. of protons |
---|---|---|
sodium | 11 | 11 |
chlorine | 17 | 17 |
Name | Formula |
---|---|
sodium ion | Na+ |
potassium ion | K+ |
calcium ion | Ca2+ |
chloride ion | Cl− |
oxide ion | O2− |
nitrate ion | NO3− |
sulfate ion | SO42− |
bicarbonate ion* | HCO3− |
'-ide' | This usually means that there are only two elements in a compound. The convention applies to both covalent and ionic compounds, e.g. carbon dioxide and sodium chloride, respectively. In ionic compounds, the name of the negative ion ends in '-ide', e.g. oxide and chloride. |
'-ium' | This usually signifies a part of a compound that comes from an element that is a metal, e.g. calcium and sodium. In ionic compounds, this part is the positive ion. |
'-ate' | This ending applies only to ionic compounds. It usually means that the negative ion itself consists of two elements, one of which is oxygen, e.g. the sulfate and nitrate ions. |
Ion | Concentration/(mg/l)* | |||||
---|---|---|---|---|---|---|
Volvic® | Vittel® | Buxton® | Evian® | Tap water | ||
Area 1 | Area 2 | |||||
calcium | 11.5 | 91.0 | 55.0 | 78.0 | 130.0 | 50.0 |
magnesium | 8.0 | 19.9 | 19.0 | 24.0 | 9.4 | 6.6 |
sodium | 11.6 | 7.3 | 24.0 | 5.0 | 51.0 | 128.0 |
potassium | 6.2 | - | 1.0 | 1.0 | 9.4 | 1.6 |
chloride | 13.5 | - | 37.0 | 4.5 | 82.0 | 27.1 |
nitrate | 6.3 | 0.6 | <0.1 | 3.5 | 26.0 | 17.6 |
sulfate | 8.1 | 105.0 | 13.0 | 10.0 | 210.0 | 21.3 |
bicarbonate | 71.0 | 258.0 | 248.0 | 357.0 | ? | ? |