Sodium

Sodium is one of about more than one hundred chemical elements, the mineral substances that make up everything in the universe. Sodium is one of the most vital chemical elements for animal life, which could not exist without it. Because of sodium's high reactivity—its ability to combine with other elements to form compounds—people have used sodium for a variety of purposes, such as to make oral rehydration salts, washing soda, baking soda, and table salt. Though nearly all foods in human diets contain some amount of sodium, consuming too much of it over long periods can cause a range of health problems, such as hypertension and kidney disease.

The Chemistry of Sodium

Pure sodium is a semisolid silver metal with a softness and composition like butter. Because it lacks much density—solidity or compactness—sodium is extremely light and can float on water. As with many metals, it conducts, or transmits, electricity and heat extremely well.

The periodic table of the elements, a scientific chart containing chemical information for all known elements, reveals more specific facts about sodium. Its chemical symbol, the lettered representation of an element's name, is "Na," which is derived from the ancient Latin word for sodium, natrium. The name "sodium" itself descends from the Latin sodanum, a word that past civilizations gave to a form of sodium that alleviated headaches. English-speaking people later referred to this chemical as “soda.”

The periodic table also provides information about sodium's atomic state. An atom is the most basic chemical unit of everything that exists. One atom of sodium has an atomic number of 11. An element's atomic number is determined by the number of protons, a type of subatomic particle, contained within one of its atoms. An atom of sodium, therefore, has eleven of each of these particles.

One of sodium's defining traits is its reactivity. The element is so versatile and so easily combines with other elements that it cannot be found in pure form in nature. Rather, sodium must be chemically extracted from compound substances such as sodium chloride, which is present naturally in sea water and forms deposits of rock salt when seawater evaporates. Over many years, people worldwide have discovered myriad uses for sodium and the range of compounds it can help create.

Human Uses of Sodium

Sodium compounds have been used to create commonplace household products such as baking soda (sodium bicarbonate), soda (sodium carbonate), paper and photographs (sodium sulfate), and borax (sodium borate), the chemical used in laundry detergents. Sodium can also be combined with small amounts of the element neon to create sodium vapor lamps. These lights are bright and inexpensive to maintain, which is why they are commonly used in stadiums and on highways.

The most common natural compound of sodium is sodium chloride, composed of sodium and chlorine, the same substance that forms oceanic rock salt. People have used this naturally occurring chemical to manufacture road salt, which is used in winter to melt snow and ice on roads. Sodium chloride also can be mixed with water and applied to pottery and ceramics as a salt glaze finish. A related process involves making substances called frits. Essential components in glassmaking, frits are made from sodium carbonate created from a sodium chloride base.

A highly popular domestic use of sodium chloride is table salt. Salt is used for many culinary purposes, including cooking, baking, preserving perishable foods, and adding extra flavor to prepared meals. Edible salt was an especially valuable commodity in less industrialized times, when countries around the world sometimes raided foreign salt mines to build up their own supplies. Although the human body requires a certain daily amount of sodium, too much can instigate a range of health problems, including increased risk of heart attack and stroke.

Sodium and Health

In proper amounts, sodium is essential to human health. It helps regulate blood pressure and blood volume while also allowing muscles to expand and contract as they should. Healthy foods that contain natural quantities of sodium include milk, celery, beets, and various other vegetables and fruits. Most processed foods available in grocery stores and restaurants, however, contain added sodium, which has been cooked or baked into the items and is impossible to separate. Foods generally high in added sodium include snack foods such as potato chips, canned foods, and frozen meats such as sausage and bacon. To promote the reduction of sodium in the average American's diet, the US Food and Drug Administration outlined "Phase I" of its Voluntary Sodium Reduction Goals. These goals aimed to reduce the average sodium intake from approximately 3,400 to 2,300 milligrams per day in 2020s.

Eating any of these foods in excess can raise a person's daily sodium intake to well above the healthy recommended amount. The United States Centers for Disease Control and Prevention (CDC) suggests that healthy adults younger than fifty-one consume no more than 2,300 milligrams of sodium daily. The CDC also urges adults older than fifty-one, especially those with histories of diabetes or heart, liver, or kidney disease, to limit their daily sodium intake to 1,500 milligrams because consuming too much sodium over an extended period can lead to hypertension, or high blood pressure. Hypertension strains the body's blood vessels; over time, this strain can increase a person's risk of suffering a heart attack or stroke.

As per the Dietary Guidelines for Americans (DGA) and the National Academies of Sciences, Engineering and Medicine (NASEM) standards, the adequate intake of potassium varies depending on age and gender. For adult males the recommended value is 3,400 milligrams of potassium a day, while the value for adult females is 2,600 milligrams of potassium a day. Potassium directly opposes sodium, working to lower blood pressure and ultimately benefit heart health. Foods naturally high in potassium include bananas, potatoes, fresh beans, broccoli, and carrots.

Bibliography

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