Chemical element, symbol: Na, atomic number: 11 and atomic weight 22,9898. It’s a soft metal, reactive and with a low melting point, with a relative density of 0,97 at 20ºC (68ºF). From the commercial point of view, sodium is the most important of all the alkaline metals.
Sodium reacts quickly with Water, and also with snow and ice, to produce sodium hydroxide and hydrogen. When it’s exposed to air, metallic sodium recently cut looses its silvery appearance and acquires an opaque grey colour due to the formation of a sodium oxide coating. Sodium doesn’t react with nitrogen, not even at very high temperatures, but it can react with ammonia to form sodium amide. Sodium and hydrogen react above 200ºC (390ºF) to form sodium hydride. Sodium hardly reacts with carbon, but it does react with halogens. It also reacts with various metallic halides to form the metal and sodium chloride. Sodium doesn’t react with paraffinic hydrocarbons, but it forms addition compounds with naphthalene and other aromatic polycyclic compounds and with aryl alkenes. The reaction of sodium with alcohols is similar to the reaction of sodium with water, but slower. There are two general reactions with organic halides. One of them requires the condensation of two organic compounds, which form halogens when those are eliminated. The second type of reaction includes the replacement of halogen by sodium, to obtain a sodium organic compound.
Sodium is a soft, silvery-white metal. It is soft enough to cut with the edge of a coin.
Freshly cut surfaces oxidize rapidly in air to form a dull, oxide coating.
Sodium burns in air with a brilliant yellow flame.
Sodium floats on water, because its density is lower than water's. It also reacts vigorously with water - violently if more than a small amount of sodium meets water (see video on left) - to produce sodium hydroxide and hydrogen gas. Sodium reacts with water more vigorously than lithium and less vigorously than potassium. Explosions occur when the heat generated by the sodium-water reaction ignites the resulting Hydrogen gas.
- Sodium in its metallic form is very important in making esters and in the manufacture of organic compounds. Sodium is also a component of sodium chloride (NaCl) a very important compount found everywhere in the living Environment. Other uses are: to improve the structure of certain Alloys; in soap, in combination with fatty acids, in sodium vapor lamps, to descal metals, to purify molten metals.
- Solid sodium carbonate is needed to make Glass.
 Sodium in the Environment
Sodium is the sixth most abundant element in The Earth’s crust, which contains 2,83% of sodium in all its forms. Sodium is, after chloride, the second most abundant element dissolved in seawater. The most important sodium salts found in nature are sodium chloride (halite or rock salt), sodium carbonate (trona or soda), sodium borate (borax), sodium nitrate and sodium sulfate. Sodium salts are found in seawater (1.05%), salty lakes, alkaline lakes and mineral spring water. The production of Salt is around 200 million tonnes per year; this huge amount is mainly extracted from salt deposits by pumping water down bore holes to dissolve it and pumping up brine. The sun and many other stars shine with visible light in which the yellow component dominates and this is given out by sodium atoms in a high-energy state.
 Health effects of sodium
Sodium is a compound of many foodstuffs, for instance of common Salt. It is necessary for humans to maintain the balance of the physical fluids system. Sodium is also required for nerve and muscle functioning. Too much sodium can damage our kidneys and increases the chances of high blood pressure. The amount of sodium a person consumes each day varies from individual to individual and from culture to culture; some people get as little as 2 g/day, some as much as 20 grams. Sodium is essential, but controversely surrounds the amount required.
Contact of sodium with Water, including perspiration causes the formation of sodium hydroxide fumes, which are highly irritating to skin, eyes, nose and throat. This may cause sneezing and coughing. Very severe exposures may result in difficult breathing, coughing and chemical bronchitis. Contact to the skin may cause itching, tingling, thermal and caustic burns and permanent damage. Contact with eyes may result in permanent damage and loss of sight.
 Environmental effects
Sodium's powdered form is highly explosive in Water and a poison combined and uncombined with many other elements.
Ecotoxicity: Median tolerance limit (TLM) for the mosquito fish, 125 ppm/96hr (fresh water); Median tolerance limit (TLM) for the bluegill, 88 mg/48hr (tap water).
Environmental fate: this chemical is not mobile in solid form, although it absorbs moisture very easily. Once liquid, sodium hydroxide leaches rapidly into the soil, possibly contaminating water sources.
 Health Benefits of Sodium
 Deficiency Symptoms
Recommended intake value of sodium is 120mg/day. But its deficiency can be harmful, as it directly attacks the nervous system of human body. In general, it leads to
Diarrhea Vomiting Headache Weakness Low blood pressure Lethargy Weight loss Confusion Dizziness Muscular irritability
Overdose of sodium causes high blood pressure, swelling of brain nerves and cerebral edema. If it worsens, it can even lead to comma.
Reduction in the amount of sodium also reduces the Fat accumulated in the periphery. It also elevates the chances of lung infection. Sodium present in plasma provides ninety percent base to the body. Depletion of sodium layer is an invitation to diseases that can cause exhaustion, exertion and mental apathy.
 Important Sources
Some of the important sources of sodium are Apple, common Salt, homemade soups, Cabbage, egg yolks, pulses, Bananas. Even, Carrots, baking powder and baking Soda, turnips, leafy vegetables and dried Peas are some of the essential sources. Processed Cheese, smoked Fish and salty meats, snacks, Pickles and sauce contains ample amount of sodium.
Generally sodium is present in very little quantity in almost every natural food. When it is added in form of common salt, it not only increases the flavor but also completes the necessary requirement of balanced diet. The health benefits of sodium include:
Water Balance: Sodium is one of those minerals, which helps to maintain water level in the human body. Sodium and water balance are very interdependent. It pumps water in the cell and regulates the amount of extra cellular fluid in the body.
Sunstroke: It is caused due to the failure of heat regulating system of the human body. This heat exhaustion is caused due to continuous exposure to very high temperature due to which the body loses its capacity to maintain the normal temperature. This condition is further aggravated due to the loss of Salt and Water from the body. Thus, Sodium plays a vital role in preventing sun stroke or heat prostration by replacing the loss of essential electrolytes. Besides water, drinking fluids containing salt and Sugar is favorable against sunstroke. Salt can also be mixed with the drink of raw Mangoes to provide more relief. It is very important for ultra endurance athletes.
Brain function: Brain is very sensitive to the change in sodium level of the body, which often leads to confusion and lethargy. Sodium aids in keeping the mind sharp. It is an important element for development of brain. Sodium facilitates the improvement of brain functions.
Muscle cramps: These are caused mostly during the hot Summer months, due to electrolyte imbalance and dehydration. Thus, apart from proper hydration of the body, it is also important to supplement one’s body with sodium rich juices and fluids to restore the amount of electrolyte.
Anti aging: Sodium is an important hydrating product of anti-aging creams. It fights with the radicals which accelerate the aging process. It helps in restoring youthful and healthy skin.
Eliminates excess carbon dioxide: Sodium plays an important role in the removal of excess amount of Carbon dioxide accumulated in the body.
Maintains glucose absorption: It helps in absorption of glucose by cells for the smooth transportations of nutrients in body cell membranes.
Maintains acid-base balance: By altering proportions of acid-base alkali phosphates it controls reaction of urine in kidneys.
Regulation of fluids: The health benefits of sodium balances the osmotic pressure in the human body due to regulation of fluid in body cells.
Balance of ions: Sodium shares an association with chlorides and bicarbonates in maintaining a sound balance between two types of ions, positively charged ions as well as negatively charged ions.
Maintains healthy condition of the heart: It maintains the contraction of heart. It plays a vital role in maintaining the blood pressure of the human body. Increase in sodium content can dramatically boost the blood pressure.
- sodium metal is used in the preparation of tetraethyl lead, PbEt4, an important anti-knock reagent in leaded petrol (gasoline) - fortunately being phased out in many countries because of lead pollution problems
- sodium metal is used in the preparation of titanium metal from TiCl4
the metal is used in the manufacture of sodamide, sodium cyanide, sodium peroxide, and sodium hydride the metal is used in the reduction of organic esters, and in the preparation of organic compounds the alloy with potassium, NaK, is an important heat transfer agent and a good chemical reducing agent (as some proportions of Na and K are liquid at room temperature).
- sodium compounds including "common salt" (sodium chloride, NaCl), "soda ash" (sodium carbonate, Na2CO3), "baking soda" (sodium bicarbonate, NaHCO3, "bicarb"), and "caustic soda" (sodium hydroxide, NaOH), are important to the Paper, Glass, soap, textile, petroleum, chemical, and metal industries
sodium vapour is used in lamps for street lighting table salt - don't use too much!
- Sodium occurs naturally in most foods. The most common form of sodium is sodium chloride, which is table salt. Milk, beets, and celery also naturally contain sodium, as does drinking water, although the amount varies depending on the source.
- Sodium is also added to various food products. Some of these added forms are monosodium glutamate, sodium nitrite, sodium saccharin, baking soda (sodium bicarbonate), and sodium benzoate. These are ingredients in condiments and seasonings such as Worcestershire sauce, soy sauce, Onion salt, Garlic salt, and bouillon cubes.
- Processed meats, such as bacon, sausage, and ham, and canned soups and vegetables are all examples of foods that contain added sodium. Fast foods are generally very high in sodium.
- For individuals who are sodium-sensitive, an increased intake of sodium may contribute to high blood pressure. Therefore, people with high blood pressure may be advised to reduce sodium intake; all patients with high blood pressure should discuss this issue with their doctor.