Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens
Halogen
The halogens or halogen elements are a group in the periodic table consisting of five chemically related elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). The artificially created element 117 (ununseptium) may also be a halogen. In the modern IUPAC nomencl…
What state of matter is iodine at room temperature?
This element is a solid. Iodine is classified as an element in the 'Halogens' section which can be located in group 7 of the Periodic Table. The halogens exist, at room temperature, in all three states of matter - Gases such as Fluorine & Chlorine, Solids such as Iodine and Astatine and Liquid as in Bromine.
What state is iodine at room temperature?
what is the melting point for iodine at 1 atm
- Pressure-Temperature Phase Diagrams (Lecture Pt3)
- The Iodine Myth
- Chemistry experiment 47 – Sublimation of Iodine
- Iodometric Titration
What is the physical state of iodine?
What is Iodine?
- Iodine with the symbol ‘I’ is a dark gray or purple blackish nonmetallic element with atomic number 53 in the Periodic Table.
- It is the least reactive and most electropositive halogen, even though it can form compounds with many elements.
- It is mainly found on Earth as the water-soluble iodide in brine pools and oceans.
What state is iodine in?
Why Iodine is a solid at room temperature? Despite intermolecular forces being a weak individual force of attraction, collectively they are very strong and the numerous forces between iodine molecules means that more heat energy is required to break these intermolecular forces and separate the molecules therefore iodine is a solid.
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Is iodide a solid liquid or gas?
solidIodinePhase at STPsolidMelting point(I2) 386.85 K (113.7 °C, 236.66 °F)Boiling point(I2) 457.4 K (184.3 °C, 363.7 °F)Density (near r.t. )4.933 g/cm341 more rows
Is iodine a state?
However, from 1930 to 1935, South Carolina had another state nickname. Back in the early 30s, South Carolina was known as “The Iodine State”.
Is iodine in liquid state?
As Mike notes, iodine can indeed be a liquid at atmospheric pressure between 113.7 oC and 184.3 oC.
Can i2 be a solid?
So, as a conclusion, the only forces that exist between iodine molecules are relatively weak London dispersion forces. Iodine exists as a solid at room temperature because the strength of these forces are in line with iodine's large electron cloud and polarizability.
Why is iodine a solid?
Despite intermolecular forces being a weak individual force of attraction, collectively they are very strong and the numerous forces between iodine molecules means that more heat energy is required to break these intermolecular forces and separate the molecules therefore iodine is a solid.
Is iodine a gas?
Iodine is a nonmetallic, nearly black solid at room temperature and has a glittering crystalline appearance.
Why does iodine go from solid to gas?
Iodine sublimes for the same reasons that all solids do: because it has some equilibrium vapor pressure an normal conditions. Now, the value of that pressure varies greatly in different solids. For many of them, it is so extremely low that for all practical reasons it can be considered non-existent.
What kind of solid is I2?
molecular solidI2 is a molecular solid. Each iodine molecule is made up of 2 iodine atoms, held together by a strong covalent bond. Each iodine molecule is held to another by weak Van Der Waal's forces.
Why iodine is solid and fluorine gas?
The boiling temperatures of halogens rise as the strength of Van der Waals forces down the group increases. As a result, the physical state of the elements decreases from gaseous fluorine to solid iodine as they progress along the group.
What are physical properties of iodine?
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.
Where is iodine found in the body?
Fifteen to 20 mg of iodine is concentrated in thyroid tissue and hormones, but 70% of all iodine in the body is found in other tissues, including mammary glands, eyes, gastric mucosa, fetal thymus, cerebro-spinal fluid and choroid plexus, arterial walls, the cervix, and salivary glands.
What is the atomic number of iodine?
Iodine is a chemical element with the symbol I and atomic number 53 . The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at 114 degrees Celsius, and boils to a violet gas at 184 degrees Celsius.
How much iodine is lethal?
The lethal dose for an adult human is 30 mg/kg, which is about 2.1–2.4 grams for a human weighing 70 to 80 kg (even if experiments on rats demonstrated that these animals could survive after eating a 14000 mg/kg dose). Excess iodine can be more cytotoxic in the presence of selenium deficiency.
What is the weakest bond in iodine?
Structure of solid iodine. The interhalogen bond in diiodine is the weakest of all the halogens. As such, 1% of a sample of gaseous iodine at atmospheric pressure is dissociated into iodine atoms at 575 °C.
How is iodine synthesised?
It can be synthesised from the reaction of iodine with fluorine gas in trichlorofluoromethane at −45 °C, with iodine trifluoride in trichlorofluoromethane at −78 °C, or with silver (I) fluoride at 0 °C. Iodine monochloride (ICl) and iodine monobromide (IBr), on the other hand, are moderately stable.
What is the color of halogens?
The halogens darken in colour as the group is descended: fluorine is a very pale yellow gas, chlorine is greenish-yellow, and bromine is a reddish-brown volatile liquid. Iodine conforms to the prevailing trend, being a shiny black crystalline solid that melts at 114 °C and boils at 183 °C to form a violet gas.
How many isotopes of iodine are there?
Of the thirty-seven known isotopes of iodine, only one occurs in nature, iodine-127. The others are radioactive and have half-lives too short to be primordial. As such, iodine is both monoisotopic and mononuclidic and its atomic weight is known to great precision, as it is a constant of nature.
How many oxidation states are there?
Oxidation states are typically represented by integers which may be positive, zero, or negative. Most elements have more than one possible oxidation state. For example, carbon has nine possible integer oxidation states from −4 to +4.
What is the density of a substance?
Since the density (ρ) of a substance is the total mass (m) of that substance divided by the total volume (V) occupied by that substance, it is obvious, the density of a substance strongly depends on its atomic mass and also on the atomic number density (N; atoms/cm 3 ),
What is the periodic table?
The periodic table is a tabular display of the chemical elements organized on the basis of their atomic numbers, electron configurations, and chemical properties. The electron configuration is the distribution of electrons of an atom or molecule (or other physical structure) in atomic or molecular orbitals. Knowledge of the electron configuration of different atoms is useful in understanding the structure of the periodic table of elements.
How are atoms determined?
The chemical properties of the atom are determined by the number of protons, in fact, by number and arrangement of electrons. The configuration of these electrons follows from the principles of quantum mechanics. The number of electrons in each element’s electron shells, particularly the outermost valence shell, is the primary factor in determining its chemical bonding behavior. In the periodic table, the elements are listed in order of increasing atomic number Z.
What is the boiling point of a substance?
The boiling point of a substance is the temperature at which this phase change (boiling or vaporization) occurs. The temperature at which vaporization (boiling) starts to occur for a given pressure is also known as the saturation temperature and at this conditions a mixture of vapor and liquid can exist together. The liquid can be said to be saturated with thermal energy. Any addition of thermal energy results in a phase transition. At the boiling point the two phases of a substance, liquid and vapor, have identical free energies and therefore are equally likely to exist. Below the boiling point, the liquid is the more stable state of the two, whereas above the gaseous form is preferred. The pressure at which vaporization (boiling) starts to occur for a given temperature is called the saturation pressure. When considered as the temperature of the reverse change from vapor to liquid, it is referred to as the condensation point.
What is the symbol for electronegativity?
Electronegativity, symbol χ, is a chemical property that describes the tendency of an atom to attract electrons towards this atom. For this purposes, a dimensionless quantity the Pauling scale, symbol χ, is the most commonly used.
Density – Atomic Mass and Atomic Number Density
Since the density (ρ) of a substance is the total mass (m) of that substance divided by the total volume (V) occupied by that substance, it is obvious, the density of a substance strongly depends on its atomic mass and also on the atomic number density (N; atoms/cm 3 ),
Density – Pressure and Temperature
The density of a material varies with temperature and pressure. This variation is typically small for solids and liquids but much greater for gases. Most materials expand when their temperatures increase. Rising temperatures make the liquid expand in a liquid-in-tube thermometer and bend bimetallic strips.
Overview
Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at 114 °C (237 °F), and boils to a violet gas at 184 °C (363 °F). The element was discovered by the French chemist Bernard Courtois in 1811 and was named two years later by Joseph Louis Gay-Lussac, after the Ancient Greek Ιώδης 'violet-coloured'.
History
In 1811, iodine was discovered by French chemist Bernard Courtois, who was born to a manufacturer of saltpetre (an essential component of gunpowder). At the time of the Napoleonic Wars, saltpetre was in great demand in France. Saltpetre produced from French nitre beds required sodium carbonate, which could be isolated from seaweed collected on the coasts of Normandy and Brittany. To isolate the sodium carbonate, seaweed was burned and the ash washed with water. …
Properties
Iodine is the fourth halogen, being a member of group 17 in the periodic table, below fluorine, chlorine, and bromine; it is the heaviest stable member of its group. (The fifth and sixth halogens, the radioactive astatine and tennessine, are not well-studied due to their expense and inaccessibility in large quantities, but appear to show various unusual properties for the group due to relativistic effects.) Iodine has an electron configuration of [Kr]4d 5s 5p , with the seven electr…
Chemistry and compounds
Iodine is quite reactive, but it is much less reactive than the other halogens. For example, while chlorine gas will halogenate carbon monoxide, nitric oxide, and sulfur dioxide (to phosgene, nitrosyl chloride, and sulfuryl chloride respectively), iodine will not do so. Furthermore, iodination of metals tends to result in lower oxidation states than chlorination or bromination; for example, rhenium metal reacts with chlorine to form rhenium hexachloride, but with bromine it forms only rhenium …
Occurrence and production
Iodine is the least abundant of the stable halogens, comprising only 0.46 parts per million of Earth's crustal rocks (compare: fluorine 544 ppm, chlorine 126 ppm, bromine 2.5 ppm). Among the 84 elements which occur in significant quantities (elements 1–42, 44–60, 62–83, 90 and 92), it ranks 61st in abundance. Iodide minerals are rare, and most deposits that are concentrated enough for economical extraction are iodate minerals instead. Examples include lautarite, Ca(IO3)2, and diet…
Applications
About half of all produced iodine goes into various organoiodine compounds, another 15% remains as the pure element, another 15% is used to form potassium iodide, and another 15% for other inorganic iodine compounds. Among the major uses of iodine compounds are catalysts, animal feed supplements, stabilisers, dyes, colourants and pigments, pharmaceutical, sanitation (from tincture of iodine), and photography; minor uses include smog inhibition, cloud seeding, an…
Biological role
Iodine is an essential element for life and, at atomic number Z = 53, is the heaviest element commonly needed by living organisms. (Lanthanum and the other lanthanides, as well as tungsten with Z = 74, are used by a few microorganisms.) It is required for the synthesis of the growth-regulating thyroid hormones thyroxine and triiodothyronine (T4 and T3 respectively, named after their number of iodine atoms). A deficiency of iodine leads to decreased production of T3 and T…
Precautions
Elemental iodine (I2) is toxic if taken orally undiluted. The lethal dose for an adult human is 30 mg/kg, which is about 2.1–2.4 grams for a human weighing 70 to 80 kg (even if experiments on rats demonstrated that these animals could survive after eating a 14000 mg/kg dose). Excess iodine can be more cytotoxic in the presence of selenium deficiency. Iodine supplementation in selenium-deficient populations is, in theory, problematic, partly for this reason. The toxicity deriv…