What Is Iodine Definition Atomic Number Electronic Configuration and Common Reactions
We all are familiar with the ads of Idoine salt that show up during the break on TV. Your favourite TV actor might be endorsing it, and you don’t know. We used to think why Idoine is so important for our bodies, that even actors are asking us to purchase it, and that too in the form of salt. Well, there are several ways Idoine as a food item helps us, but the benefits don’t stop there. Today we are going to talk about one of the most important chemical elements that you use in your daily life.
Idoine is something that we are using from the very beginning in lots of ways when humankind started cooking food on fire. One of the essential chemicals that we need to survive is Iodine, and our bodies can make it on their own. As a result, we have to rely on food items to compensate for Iodine’s deficiency. As a rule, set by the government, there is a tiny amount of Iodine that could be present in food items unless it has been added during the food processing to keep it fresh and ready to eat for a long time.
Food that has been processed comes with more Iodine due to the presence of iodized salt. In addition to this, if you are thinking about how companies are getting Iodine and whether their Iodine is safe to eat or not? Well, the answer is, most of the Iodine comes from the natural resource, which is our oceans, where it found in large amounts in seaweed.
The Iodine atomic number is 53, in its natural occurrence, it is present in the form of dark grey or purplish colour. It is a part of the halogen element in the periodic table. All the halogens show quite a resemblance in their chemical nature, and the same happens when they form a compound in their general chemical behaviour.
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The Iodine was first extracted from the seaweed by French Chemist Dr Bernard Courtois when he tried to burn the seaweed and got violet colour ashes along with sulfuric acid as a by-product of the experiment. He didn’t know what to call this chemical, so he named it “chemical X.” After that, Sir Humphry Davy was going to Italy from Paris, and on his way, he found that “chemical X” is analogous to chlorine and came with the name Iodine, which means violet colour in Greek.
The atomic mass of Iodine is 126.904, and it is the least reactive halogen. Besides this property, it comes second in the list of electropositive halogens. Iodine is also used in photography and dyes, creating several medicines in the field of medical science.
What Is Iodine?
When talking about the Iodine electron configuration, we first need to know what does it mean by electronic configuration. In terms of chemistry, the electron configuration is the arrangement of electrons in different orbits of an atom or given molecule. Now, if we look at the Iodine electron configuration, we will have this, which is written down below.
1s22s22p63s23p63d104s24p64d105s25p5 , 2-8-18-18-7
Also, Iodine symbol is (I), yes, that’s it, this is how you are going to represent Iodine when you are using it to show the chemical reactions between the two compounds and elements.
The (i) element is quite easy to remember, and its oxidation states are -1, +1, +3, +5, and +7. Likewise, the only stable Iodine which occurs naturally on earth is iodine-127. On the other hand, we have an exceptionally useful isotope of Iodine, which is present in the radioactive form, and this isotope is iodine-131.
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The atomic weight of Iodine is 126.9044. The presence of Iodine in seawater is not magnificent, because you can get only 50 mg of Iodine per metric ton of seawater. But seaweeds are the best resource for extracting Iodine, and most of the Iodine that is present in our food comes from there.
Uses of Iodine
The mass of Iodine makes it a unique element for producing images with the help of a piece of metal. As a result, Iodine made it possible for photography to go commercial; this technique was invented by Louis Daguerre in 1839.
In the modern world, we see a lot of commercial Iodine uses, salts such as Iodide are being used as disinfectants and in pharmaceutical companies to produce medicines.
Furthermore, it is used to print inks and dyes and to create a catalyst to speed up the chemical reaction.
Lastly, one of the most common uses of Iodine is in table salt. It is present in the low amount but helps avoid the iodine deficiency that can lead to malfunctioning of the thyroid gland, resulting in swelling of Goitre in the human body.
FAQs on Iodine Element in Chemistry Structure Properties and Applications
1. What is iodine in chemistry?
Iodine is a chemical element with the symbol I and atomic number 53 that belongs to the halogen group (Group 17) of the periodic table. It is a non-metal and exists as diatomic molecules, I2, in its elemental form.
- Period: 5
- Group: 17 (halogens)
- Physical state at room temperature: dark purple-black solid
- Vapour colour: violet
2. What is the electronic configuration of iodine?
The electronic configuration of iodine (Z = 53) is [Kr] 4d10 5s2 5p5. This means iodine has seven valence electrons in its outermost shell.
- Total electrons: 53
- Valence shell: 5s2 5p5
- Valence electrons: 7
3. Why is iodine classified as a halogen?
Iodine is classified as a halogen because it is a Group 17 element with seven valence electrons and forms -1 charged ions. Like other halogens, it:
- Exists as diatomic molecules (I2)
- Forms hydrogen halides such as HI
- Forms ionic salts with metals, e.g., 2Na(s) + I2(s) → 2NaI(s)
4. What is the oxidation state of iodine in its compounds?
Iodine commonly exhibits oxidation states of -1, +1, +3, +5, and +7 in its compounds. The most common oxidation state is -1 in iodide salts such as KI.
- -1 in iodides (e.g., NaI)
- +5 in iodate ion (IO3-)
- +7 in periodate ion (IO4-)
5. What happens when iodine reacts with hydrogen?
When iodine reacts with hydrogen, it forms hydrogen iodide (HI) in a reversible reaction. The balanced chemical equation is:
- H2(g) + I2(g) ⇌ 2HI(g)
6. How does iodine react with metals?
Iodine reacts with metals to form metal iodides through a redox reaction. For example:
- 2Na(s) + I2(s) → 2NaI(s)
- Sodium is oxidized: Na → Na+ + e-
- Iodine is reduced: I2 + 2e- → 2I-
7. What is the test for iodine in the laboratory?
Iodine is identified by its characteristic violet vapour and by forming a blue-black complex with starch. The iodine–starch test is commonly used to detect iodine.
- Add a few drops of iodine solution to starch.
- A deep blue-black colour confirms the presence of iodine.
8. Why does iodine sublime when heated?
Iodine sublimes because its solid molecules (I2) are held together by weak London dispersion forces that are easily overcome by heat. On heating:
- I2(s) → I2(g)
9. What is the difference between iodide and iodine?
Iodine refers to the neutral element I2, while iodide is the negatively charged ion I-. The key differences are:
- Iodine (I2): diatomic molecule, oxidation state 0
- Iodide (I-): monatomic ion, oxidation state -1
10. What are the common uses of iodine in chemistry and industry?
Iodine is widely used as an antiseptic, in iodized salt, and in the synthesis of organic and inorganic compounds. Important uses include:
- Antiseptic solutions (e.g., tincture of iodine)
- Production of iodized salt containing KI or KIO3
- Preparation of silver iodide (AgI) in photography
- Use in analytical chemistry for iodometric titrations
