THE ELEMENT IODINE - Solid iodine is blue-black in color, with a metallic sheen. Iodine is slightly soluble in water and more soluble in nonpolar solvents. Iodine is a halogen, which is a type of non-metal. The thyroid gland uses iodine to make the hormones thyroxine and triiodotyronine. Insufficient iodine leads to development of a goiter, which is a swelling of the thyroid gland. Iodine deficiency is believed to be the leading preventable cause of mental retardation. Excessive iodine symptoms are similar to those of iodine insufficiency. Iodine toxicity is more severe if a person has a selenium deficiency. Iodine is used extensively in medicine. Sensitive individuals may develop a rash when swabbed with tincture of iodine. In rare cases, anaphylactic shock has resulted from medical exposure to iodine. Potassium iodide is used in radiation pills. Natural food sources of iodine are seafood, kelp and plants grown in iodine-rich soil. Potassium iodide often is added to table salt to produce iodized salt.

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The Element Iodine

10 Iodine Facts (Atomic Number 53 or I)

Facts about the Element Iodine

by Anne Marie Helmenstine, Ph.D. 

Iodine is element 53 on the periodic table, with element symbol I.

Iodine is an element you encounter in iodized salt and some dyes.

A small amount of iodine is essential for nutrition, while too much is toxic. Here are facts about this interesting, colorful element.

The Name

Iodine comes from the Greek word iodes, which means violet. Iodine vapor is violet-colored.

The element was discovered in 1811 by French chemist Bernard Courtois.

Courtois discovered iodine by accident while he was making saltpeter for use in the Napoleonic Wars.

Making saltpeter required sodium carbonate. To get sodium carbonate, Courtois burned seaweed, washed the ash with water, and added sulfuric acid to remove contaminants.

Courtois discovered adding an excess of sulfuric acid produced a cloud of purple vapor.

While Courtois believed the vapor was a previously unknown element, he couldn't afford to research it, so he offered samples of the gas to his friends, Charles Bernard Desormes and Nicolas Clement.

They characterized the new material and made Courtois' discovery public.

Isotopes

Many isotopes of iodine are known. All of them are radioactive except for I-127, which is the only isotope found in nature.

Because there is only one natural isotope of iodine, its atomic weight is precisely known, rather than an average of isotopes like most elements.

Color and Other Properties

Iodine is element 53 on the periodic table, with element symbol I.

Iodine is an element you encounter in iodized salt and some dyes.

A small amount of iodine is essential for nutrition, while too much is toxic. Here are facts about this interesting, colorful element.

The Name

Iodine comes from the Greek word iodes, which means violet. Iodine vapor is violet-colored.

The element was discovered in 1811 by French chemist Bernard Courtois.

Courtois discovered iodine by accident while he was making saltpeter for use in the Napoleonic Wars.

Making saltpeter required sodium carbonate. To get sodium carbonate, Courtois burned seaweed, washed the ash with water, and added sulfuric acid to remove contaminants.

Courtois discovered adding an excess of sulfuric acid produced a cloud of purple vapor.

While Courtois believed the vapor was a previously unknown element, he couldn't afford to research it, so he offered samples of the gas to his friends, Charles Bernard Desormes and Nicolas Clement.

They characterized the new material and made Courtois' discovery public.

Isotopes

Many isotopes of iodine are known. All of them are radioactive except for I-127, which is the only isotope found in nature.

Because there is only one natural isotope of iodine, its atomic weight is precisely known, rather than an average of isotopes like most elements.

Color and Other Properties

Solid iodine is blue-black in color, with a metallic sheen.

At ordinary temperatures and pressures, iodine sublimates into its violet gas, so the liquid form is not seen.

The color of iodine follows a trend seen in the halogens: they appear progressively darker as you move down the group of the periodic table.

This trend happens because the wavelengths of light absorbed by the elements increases due to the behavior of the electrons.

Iodine is slightly soluble in water and more soluble in nonpolar solvents. Its melting point and boiling point are the highest of the halogens.

The bond between atoms in the diatomic molecule is the weakest in the element group.

Halogen

Iodine is a halogen, which is a type of non-metal. It is located beneath fluorine, chlorine, and bromine on the periodic table, making it the heaviest stable element in the halogen group.

Thyroid

The thyroid gland uses iodine to make the hormones thyroxine and triiodotyronine.

Insufficient iodine leads to development of a goiter, which is a swelling of the thyroid gland.

Iodine deficiency is believed to be the leading preventable cause of mental retardation.

Excessive iodine symptoms are similar to those of iodine insufficiency.

Iodine toxicity is more severe if a person has a selenium deficiency.

Compounds

Iodine occurs in compounds and as the diatomic molecule I₂.

Medical Purpose

Iodine is used extensively in medicine. However, some people develop a chemical sensitivity to iodine.

Sensitive individuals may develop a rash when swabbed with tincture of iodine.

In rare cases, anaphylactic shock has resulted from medical exposure to iodine. Potassium iodide is used in radiation pills.

Food Source

Natural food sources of iodine are seafood, kelp and plants grown in iodine-rich soil. Potassium iodide often is added to table salt to produce iodized salt.

Atomic Number

The atomic number of iodine is 53, meaning all atoms of iodine possess 53 protons.

Commercial Source

Commercially, iodine is mined in Chile and extracted from iodine-rich brine, notably from the oilfields in the US and Japan. Prior to this, iodine was extracted from kelp.

Iodine Element Fast Facts

·  Element Name: Iodine

·  Element Symbol: I

·  Atomic Number: 53

·  Atomic Weight: 126.904

·  Group: Group 17 (Halogens)

·  Period: Period 5

·  Appearance: Metallic blue-black solid; violet gas

·  Electron Configuration: [Kr] 4d¹⁰ 5s² 5p⁵

·  Melting Point: 386.85 K ​(113.7 °C, ​236.66 °F)

·  Boiling Point: 457.4 K ​(184.3 °C, ​363.7 °F)

Anne Marie Helmenstine, Ph.D.

Chemistry Expert

Education

Ph.D., Biomedical Sciences, University of Tennessee at Knoxville

B.A., Physics and Mathematics, Hastings College

Introduction

Ph.D. in biomedical sciences from the University of Tennessee at Knoxville - Oak Ridge National Laboratory.

Science educator with experience teaching chemistry, biology, astronomy, and physics at the high school, college, and graduate levels.

ThoughtCo and About Education chemistry expert since 2001.

Widely-published graphic artist, responsible for printable periodic tables and other illustrations used in science.

Experience

Anne Helmenstine, Ph.D. has covered chemistry for ThoughtCo and About Education since 2001, and other sciences since 2013. She taught chemistry, biology, astronomy, and physics at the high school, college, and graduate levels. She has worked as a research scientist and also abstracting and indexing diverse scientific literature for the Department of Energy.

In addition to her work as a science writer, Dr. Helmenstine currently serves as a scientific consultant, specializing in problems requiring an interdisciplinary approach. Previously, she worked as a research scientist and college professor. 

Education

Dr. Helmenstine holds a Ph.D. in biomedical sciences from the University of Tennessee at Knoxville and a B.A. in physics and mathematics with a minor in chemistry from Hastings College. In her doctoral work, Dr. Helmenstine developed ultra-sensitive chemical detection and medical diagnostic tests.

ThoughtCo and Dotdash

ThoughtCo is a premier reference site focusing on expert-created education content. We are one of the top-10 information sites in the world as rated by comScore, a leading Internet measurement company. Every month, more than 13 million readers seek answers to their questions on ThoughtCo.

For more than 20 years, Dotdash brands have been helping people find answers, solve problems, and get inspired. We are one of the top-20 largest content publishers on the Internet according to comScore, and reach more than 30% of the U.S. population monthly. Our brands collectively have won more than 20 industry awards in the last year alone, and recently Dotdash was named Publisher of the Year by Digiday, a leading industry publication.

https://www.thoughtco.com/facts-about-iodine-607974

WATER PURIFYING CHEMICALS - Drinking untreated water, which can contain various pathogens, can lead to illness ranging from mild gastrointestinal symptoms like nausea, vomiting, and diarrhea to more severe illnesses like hepatitis, meningitis, and even death. Water purifying chemicals can be added to untreated water to kill harmful microorganisms (protozoa, bacteria, and viruses). They can be useful following a natural disaster that disturbs the supply of drinkable water or for people who are camping, hiking, or find themselves in remote areas where safe drinking water is not readily available. Water purifying chemicals available today are most commonly in the form of tablets, but they are also available in liquid drops or packaged powder. They contain either chlorine or iodine. These disinfectants act directly on harmful organisms to destroy them.

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Water Purifying Chemicals

Are Water Purifying Chemicals Safe?

Poison Control

The Bottom Line

Portable water purification chemicals are available in tablet, liquid, and powder form and contain the disinfectants iodine or chlorine.

They can be added to untreated water to kill harmful microorganisms and make the water safer to drink. Although generally safe, they can easily be mistaken for medications or candy.

The Full Story

Perhaps you are an adventurer hiking in the wilderness and realize you are out of bottled water.

There is a stream up ahead; you are quite thirsty and the water looks clean.

Or perhaps your town was just hit hard by a hurricane, disrupting and contaminating your water supply.

In situations like these, it is risky to drink untreated water. Portable water purifying products can come in handy and are marketed for use in these kinds of situations.

Drinking untreated water, which can contain various pathogens, can lead to illness ranging from mild gastrointestinal symptoms like nausea, vomiting, and diarrhea to more severe illnesses like hepatitis, meningitis, and even death.

According to the Waterborne Disease and Outbreak Surveillance System (WBDOSS), in the United States during 2013-2014, 42 water-associated outbreaks were reported. These outbreaks resulted in at least 1006 cases of illness, 124 hospitalizations, and 13 deaths.

Water purifying chemicals can be added to untreated water to kill harmful microorganisms (protozoa, bacteria, and viruses) and make the water safer to drink.

They can be useful following a natural disaster that disturbs the supply of drinkable water or for people who are camping, hiking, or find themselves in remote areas where safe drinking water is not readily available.

Water purifying chemicals available today are most commonly in the form of tablets, but they are also available in liquid drops or packaged powder. They contain either chlorine or iodine.

Whether liquid, tablets, or powder, water purifying chemicals are added directly to untreated water, releasing the chlorine or iodine.

These disinfectants act directly on harmful organisms to destroy them.

Water purifying chemicals vary in their shelf-life, length of time required for them to fully dissolve and be effective, and the concentration of the active ingredient.

How well each chemical is able to destroy harmful pathogens and make untreated water truly safe to drink depends on multiple factors like the temperature, pH, cloudiness of the water, and how long the chemical is left to dissolve and fully take effect.

It is important to note that not all pathogens will be completely eliminated by these chemicals. According to the Centers for Disease Control and Prevention (CDC), proper boiling of untreated water is the most effective technique, but this is often not practical.

Furthermore, water purifying chemicals do not rid the water of chemical contaminants like pesticides.

How safe are water purifying chemicals and can they be poisonous? When used correctly, water purifying chemicals are generally safe.

They themselves are a safety measure intended to be consumed, after all!

However, when in tablet form, they can easily be mistaken for medications, vitamins, or candy, and children who gain access to them can swallow them.

Water purifying chemicals are quite irritating.

When used inappropriately, excessively, or when swallowed whole, they lead to immediate irritation of the mouth, throat, and stomach causing symptoms such as burning and irritation in the mouth and throat, nausea, vomiting, and abdominal pain.

Iodine-based water purifiers can lead to more severe, delayed and body-wide effects especially when used over a prolonged period of time.

The risk of poisoning from water purifying chemicals depends on many different factors such as a patient's age and overall health and the amount and type of product swallowed.

Portable water purifying products have been around for many years and can be useful tools for reducing water-borne diseases.

Unintentional ingestions of these products can occur because they look very similar to edible items.

Keeping these products in their original packaging and separate from areas where food and medications are stored can help avoid unintentional exposures.

Another important poison-prevention tip is to pay close attention to and follow the directions for each product; the chemicals' safety and effectiveness depend on it.  

·          Store water purification chemicals out of reach and sight of children, preferably in cabinets with child-resistant closures.

·          Keep water purification chemicals in their original container and away from food or medicines.

·          Use water purification products only as directed by the manufacturer and for their intended purpose.

This Really Happened

A 13-month-old boy opened a bottle of water purifying liquid containing chlorine dioxide. Relatives who were visiting from overseas had brought it with them.

The boy's father was concerned that the boy might have swallowed some of it and called Poison Control for advice.

After interviewing the father, Poison Control determined that the boy would be able to tolerate the small amount he might have swallowed.

Since chlorine dioxide is quite irritating, the father was advised to give the child fluids to drink and to monitor for nausea, vomiting, and signs of mouth or throat irritation. Fortunately, no symptoms developed.

If you have any questions about water purifying products or if someone has been exposed to a water purifying chemical, check the webPOISONCONTROL^® online tool or call Poison Control at 1-800-222-1222 for guidance.

Serkalem Mekonnen, RN, BSN, MPH
Certified Specialist in Poison Information

Kristina Yee, BS, PharmD
Certified Specialist in Poison information

Poison Control tells you what to do if you swallow, splash, or get stung by something that might be harmful.

Use webPOISONCONTROL® online, or call. Both services are free and confidential.

https://www.poison.org/articles/are-water-purifying-chemicals-safe-183

IODINE BASIC FACTS - Iodine is a lustrous blue-black solid which volatizes at room temperature into a violet-blue gas with an irritating odor. Iodine forms compounds with many elements, but it is less reactive than the other halogens, which will displace it. Iodine also possesses some properties typical of metals. Iodine is only slightly soluble in water, although it dissolves readily in carbon tetrachloride, chloroform, and carbon disulfide, forming purple solutions. Iodine will bind to starch and color it deep blue. Although iodine is essential for proper nutrition, care is needed when handling the element, as skin contact can cause lesions and the vapor is highly irritating to the eyes and mucous membranes.

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Iodine Basic Facts

Periodic Table Element Facts: Iodine

by Anne Marie Helmenstine, Ph.D. 

Iodine Basic Facts

Atomic Number: 53

Iodine Symbol: I

Atomic Weight: 126.90447

Discovery: Bernard Courtois 1811 (France)

Electron Configuration: [Kr] 4d¹⁰ 5s² 5p⁵

Word Origin: Greek iodes, violet

Isotopes: Twenty-three isotopes of iodine are known. Only one stable isotope is found in nature, I-127.

Properties

Iodine has a melting point of 113.5°C, a boiling point of 184.35°C, a specific gravity of 4.93 for its solid state at 20°C, a gas density of 11.27 g/l, with a valence of 1, 3, 5, or 7.

Iodine is a lustrous blue-black solid which volatizes at room temperature into a violet-blue gas with an irritating odor.

Iodine forms compounds with many elements, but it is less reactive than the other halogens, which will displace it.

Iodine also possesses some properties typical of metals. Iodine is only slightly soluble in water, although it dissolves readily in carbon tetrachloride, chloroform, and carbon disulfide, forming purple solutions.

Iodine will bind to starch and color it deep blue. Although iodine is essential for proper nutrition, care is needed when handling the element, as skin contact can cause lesions and the vapor is highly irritating to the eyes and mucous membranes.

Uses

The radioisotope I-131, with a half-life of 8 days, has been used to treat thyroid disorders. Insufficient dietary iodine leads to the formation of a goiter.

A solution of iodine and KI in alcohol is used to disinfect external wounds. Potassium iodide is used in photography.

Sources

Iodine is found in the form of iodides in seawater and in the seaweeds which absorb the compounds.

The element is found in Chilean saltpeter, and nitrate-bearing earth (caliche), brackish waters from salt wells and oil wells, and in brines from old sea deposits.

Ultrapure iodine may be prepared by reacting potassium iodide with copper sulfate.

Element Classification: Halogen

Iodine Physical Data

Density (g/cc): 4.93

Melting Point (K): 386.7

Boiling Point (K): 457.5

Appearance: shiny, black nonmetallic solid

Atomic Volume (cc/mol): 25.7

Covalent Radius (pm): 133

Ionic Radius: 50 (+7e) 220 (-1e)

Specific Heat (@20°C J/g mol): 0.427 (I-I)

Fusion Heat (kJ/mol): 15.52 (I-I)

Evaporation Heat (kJ/mol): 41.95 (I-I)

Pauling Negativity Number: 2.66

First Ionizing Energy (kJ/mol): 1008.3

Oxidation States: 7, 5, 1, -1

Lattice Structure: Orthorhombic

Lattice Constant (Å): 7.720

Anne Marie Helmenstine, Ph.D.

Introduction

Ph.D. in biomedical sciences from the University of Tennessee at Knoxville - Oak Ridge National Laboratory.

Science educator with experience teaching chemistry, biology, astronomy, and physics at the high school, college, and graduate levels.

ThoughtCo and About Education chemistry expert since 2001.

Widely-published graphic artist, responsible for printable periodic tables and other illustrations used in science.

Experience

Anne Helmenstine, Ph.D. has covered chemistry for ThoughtCo and About Education since 2001, and other sciences since 2013. She taught chemistry, biology, astronomy, and physics at the high school, college, and graduate levels. She has worked as a research scientist and also abstracting and indexing diverse scientific literature for the Department of Energy.

In addition to her work as a science writer, Dr. Helmenstine currently serves as a scientific consultant, specializing in problems requiring an interdisciplinary approach. Previously, she worked as a research scientist and college professor. 

Education

Dr. Helmenstine holds a Ph.D. in biomedical sciences from the University of Tennessee at Knoxville and a B.A. in physics and mathematics with a minor in chemistry from Hastings College. In her doctoral work, Dr. Helmenstine developed ultra-sensitive chemical detection and medical diagnostic tests.

ThoughtCo and Dotdash

ThoughtCo is a premier reference site focusing on expert-created education content. We are one of the top-10 information sites in the world as rated by comScore, a leading Internet measurement company. Every month, more than 13 million readers seek answers to their questions on ThoughtCo.

For more than 20 years, Dotdash brands have been helping people find answers, solve problems, and get inspired. We are one of the top-20 largest content publishers on the Internet according to comScore, and reach more than 30% of the U.S. population monthly. Our brands collectively have won more than 20 industry awards in the last year alone, and recently Dotdash was named Publisher of the Year by Digiday, a leading industry publication.

https://www.thoughtco.com/iodine-facts-606546