The Element Nitrogen

Introduction to Nitrogen

Nitrogen is the 7th element on the periodic table. It is positioned at the center of the elements of life. therefore, around nitrogen are the elements carbon, oxygen, phosphorous, sulfur, and silicon. In addition to being the element that composes the majority of the earth’s atmosphere, nitrogen is essential to the formation of DNA, proteins, and plant fertilizers. Being one of the most common elements both on earth and in the universe, there is no shortage of uses for nitrogen, including agriculture, medicine, and transportation.

Ten interesting facts about nitrogen

• Nitrogen is colorless, odorless, and tasteless
• Nitrogen is the 5th most abundant element in the universe
• Nitrogen-based fertilizers are responsible for approximately 40-60% of global food production
• There are 16 known isotopes of nitrogen, but only two of them are stable
• Liquid nitrogen flash freezes foods to preserve flavor and micronutrients
• Nitrogen makes up 78% of earths atmosphere, and 95% of the atmosphere of Titan, the largest moon of Saturn
• Nitric acid (HNO₃) is used to “age” wood in the industries of woodworking and metal etching
• The human body is approximately 3% nitrogen by weight
• The orange, blue, and violet colors of the Aurora Borealis owe their luster to nitrogen
• Two nitrogen atoms will form a very strong triple bond, making diatomic nitrogen an indespensible component in robust materials, such as kevlar

Nitrogen in the Periodic Table

Nitrogen, atomic symbol N, has an atomic number of seven and lies in period two on the periodic table, above phosphorous and left of oxygen. The element is in the 15th group, so it is classified as a pnictogen (more commonly referred to as the nitrogen group or family). Nitrogen lies to the right of the metalloid stairstep, so it is a nonmetal. Like phosphorus, it has five valence electrons and has a charge of +3.

Nitrogen has an electronegativity of 3.04 on the Pauling scale. Its electron configuration is 1s²2s²2p³.

The Element Nitrogen in our Bodies

Nitrogen is a vital component of numerous bodily processes and biological systems. All amino acids contain nitrogen. Amino acids are the building blocks of proteins, which make up most of the dry weight of the human body.

Having a positive nitrogen balance is strongly associated with athletic performance, body composition, and overall metabolic health. This state is often achieved through a high-protein diet, consistent exercise, or alternatively, puberty/adolescent development.

Nitrogen is also a constituent of DNA, as well as various hormones and signaling molecules in the body.

Applications of Nitrogen in the World Today

Medicine

Radioactive nitrogen-13 isotopes are produced for use in PET scans (positive emission tomography). A PET scan is an imaging process that produces 3-dimensional pictures of bodily processes. These scans are critical to evaluate illnesses such as cancer and tumors.

Athletes with muscle-related injuries take supplements that increase the uptake of nitric oxide within the body. NO is vital to muscle and bone recovery.

Nitrous oxide (N₂O) is the active ingredient in laughing gas, an anesthetic administered prior to surgery.

Liquid Nitrogen

Liquid nitrogen is used principally as a refrigerant, for purposes such as the preservation of biologically active lab samples. In liquid form, nitrogen has a temperature of -320^oF. Due to this temperature, immersing a substance in liquid nitrogen flash freezes (freezes almost instantly) the sample. This technique preserves sells and tissues more closely to their current state than conventional freezing methods.

It can also be used to remove undesirable tissues from the skin, such as warts, skin tags, and pre-cancerous cells. Using liquid nitrogen in this way is referred to as cryotherapy.

Agriculture

Nitrogen-based fertilizers entirely revolutionized the global food supply in the 20th century. The Haber-Bosch process was devised to produce ammonia in the first decade of the 1900s. Ammonia and oxygen combine to generate nitric acid (HNO₃), which is crucial to the production of plant fertilizers. Subsequently, the advent of artificial plant fertilizers is ultimately what made the population boom of the early 20th century possible.

Today excess nitrogen fertilizer usage is trying to be reduced. The excess nitrogen from spraying on crops runs off in water to other ecosystems (such as woodlands, streams, and other waterways) and causes imbalance. The imbalance leads to algae blooms and damage to other sensitive plants.

Nitrogen in Explosives

Perhaps a more spectacular use of nitrogen is in explosives. Nitrogen and oxygen combine with more flammable substances such as sulfur and charcoal. The primary ingredient in gunpowder is potassium nitrate. When ignited, the heat breaks down the potassium nitrate, releasing oxygen to react with the sulfur and charcoal.

High explosives work similarly. The most notable difference, however, is that both the fuel and oxygen are combined into the same molecule prior to detonation. Nitroglycerin, for example, contains three carbons, each attached to a nitrogen and three oxygens, each valence electron pair on the outside populated by hydrogens. Apply an impulsive force, such as a strike from a hammer, and these atoms will rearrange, yielding oxides of carbon and nitrogen, diatomic nitrogen, water, and heat.

When and how was nitrogen discovered?

The History of Nitrogen

In 1772, French chemist Antoine Lavoisier became the first scientist to recognize clearly the elemental status of nitrogen, oxygen, and hydrogen. Scottish chemist and botanist Daniel Rutherford first isolated nitrogen later that year. He initially coined the term “noxious air” before the new element would receive its name.

Where is nitrogen found in the universe?

Nitrogen is by far the most abundant element in the earth’s atmosphere. Comparatively, the atmosphere of other planets and moons contain small quantities of nitrogen. As a nonmetal, it is not abundant in Earth’s crust. It is not present in large quantities in stars, unlike hydrogen and helium.

Nitrogen Chemistry- Compounds, Reactions Oxidation states, Isolation

Chemical Properties of the Element Nitrogen

Diatomic nitrogen is relatively inert. Alternatively, atomic nitrogen is highly reactive. It is triradical, meaning it has three unpaired electrons. Therefore, atomic nitrogen isn’t often found in nature. Diatomic nitrogen is the primary form of pure nitrogen. Atomic nitrogen is primarily lab-sourced. In fact, nitrogen is one of the seven elements primarily found in the diatomic state.

One notable reaction of nitrogen occurs in nature when lightning or a spark is present. When this happens, nitrogen reacts with diatomic oxygen, generating electrical discharge.

Nitrogen Compounds

The element nitrogen readily forms compounds with fellow nonmetals as well as metals, making for a wide variety of combinations and subsequent applications.

Nitrous oxide (N₂O)

A sweet-tasting “laughing gas”, used to nullify the pain of medical procedures.

Nitrogen Dioxide (NO₂)

A major air pollutant that comes from vehicular exhaust.

Nitroglycerin (C₃H₅N₃O₉)

A dense, high explosive, often detonated via impact.

Ammonia (NH₃)

A basic compound used in the synthesis of numerous nitrogen compounds. The compound also works as plant fertilizer.

Hydrazine (N₂H₄)

A colorless, odorless gas used as the ignition for rocket fuel.

Ammonium Nitrate (NH₄NO₃)

A salt of ammonia and nitric acid. It acts as both the nitrogenous component of many fertilizers and as an explosive when combined with fuel oil.

Hydrogen Cyanide (HCN)

The highly volatile and toxic gas used in numerous industrial processes, including fumigation.

Boron Nitride (BN)

An extremely hard compound, primarily used as a high-temperature abrasive.

Cyanogen (CN)₂

A chemical intermediate and fumigant.

Lead Azide (Pb(N₃)₂)

A detonator compound for chemical explosives.

Isolation of Nitrogen

Cryogenic distillation is the most frequently applied method of isolating nitrogen. In this process various gases cool into liquids, with some gases achieving liquid form before others, based on differing boiling points. Therefore, gases with higher boiling points change phase first.

Nitrogen Oxidation States

The most typical oxidation state of nitrogen is +5.

Physical Properties of Nitrogen

• Symbol: N
• Melting Point (celsius): -210
• Boiling Point (celsius): -195.8
• Density (g/cm³): 0.808 (liquid)
• Atomic mass: 14 amu
• Atomic number: 7
• Electronegativity (Pauling scale): 3.04
• Classification: Nonmetal, pnictogen
• Atmospheric abundance: 78% on earth
• Key isotopes: N-14, N-15
• Toxicity: Above 150 ppm for 30 mins
• Electron configuration: 1s²2s²2p³

Where can I buy elemental nitrogen?

Elemental nitrogen is relatively easy to purchase. Retail welding stores or some online retailers sell gaseous nitrogen. Liquid nitrogen is also easy to obtain. Many varieties of retailers, from all-purpose stores to chemical manufacturers for instance, sell liquid nitrogen.

Experiments with the element nitrogen

Many experiments use nitrogen in either its liquid or gas state. Nitrogen may act as either a temperature control, or as a reactant.

Chemistry demonstrations commonly utilize liquid nitrogen to create fog or freeze items. For example, you can freeze various items in liquid nitrogen and dramatically change their properties. A bouncy ball will no longer bounce for example! A video of this demonstration by Prof Shakhashiri of Science is Fun can be found here!