Here you’ll find 4 Chemical Elements that start with I, organized from “Indium” to “Iron”. These elements include metals and a halogen commonly used in electronics, medicine, catalysts, and construction. See the A–Z index to browse other letters.
Chemical Elements that start with I are the set of elements whose English names begin with the letter I. Notably, iron helped shape human history during the Iron Age and remains central to industry.
Below you’ll find the table with Name, Symbol, Atomic number, Standard atomic weight, and Discovery year.
Name: The element’s full name, which helps you identify and compare elements by common vocabulary quickly.
Symbol: The one- or two-letter abbreviation you use to read formulas and recognize elements at a glance.
Atomic number: The whole-number proton count; you use it to order elements and understand periodic trends quickly.
Standard atomic weight: The average mass you use for calculations and comparisons, given with three decimals for precision.
Discovery year: The historical date or era when the element was first identified, useful for historical context.
Chemical Elements that start with I
| Name | Atomic Number | Standard Atomic Weight (u) | Discovery Year | Description |
|---|---|---|---|---|
| Iron | 26 | 55.85 | Antiquity | Abundant, strong transition metal essential to construction and biology (hemoglobin); known and used since antiquity. |
| Indium | 49 | 114.82 | 1863 | Soft, silvery post-transition metal used in electronics (indium tin oxide); notable for a low melting point and good ductility. |
| Iodine | 53 | 126.90 | 1811 | Dark violet nonmetal used in medicine, disinfection, and nutrition; essential for thyroid hormones, discovered in 1811. |
| Iridium | 77 | 192.22 | 1803 | Very hard, dense, corrosion-resistant precious metal used in high-temperature alloys and catalysts; extremely rare in Earth’s crust. |