Interactive Periodic Table
All 118 elements. Tap a tile to read its data, recolour the chart by trend, or jump into a calculator when the homework starts.
Swipe sideways to see the whole table →
- Alkali metals
- Alkaline earth metals
- Transition metals
- Post-transition metals
- Metalloids
- Reactive nonmetals
- Halogens
- Noble gases
- Lanthanides
- Actinides
Iron
Transition metal · d-block · period 4, group 8
- Electron configuration
- [Ar] 3d6 4s2
- Valence electrons
- 8
- Common charges
- 2+, 3+
- Electronegativity
- 1.83
- Atomic radius
- 125 pm
- 1st ionization energy
- 763 kJ/mol
Chemistry calculators
Each one shows its working, so you can check the method as well as the answer.
- Molar mass calculatorFormula to g/mol, % composition, grams ↔ moles.
- Chemical equation balancerBalance any equation, including ionic and redox.
- Electron configuration calculatorFull and noble-gas notation, orbital diagrams, ions.
- Molarity calculatorSolve for molarity, mass, moles or volume.
- Dilution calculatorC₁V₁ = C₂V₂ for stock solutions.
- Stoichiometry & limiting reactant calculatorMasses from a balanced equation, limiting reagent, yield.
- Percent yield calculatorActual vs theoretical yield.
- Empirical formula calculatorPercent or grams to empirical and molecular formula.
- Oxidation number calculatorOxidation state of every atom in a formula.
- Valence electrons calculatorValence electrons for any element, with a chart.
- pH calculatorpH, pOH, [H⁺], [OH⁻]; strong and weak acids and bases.
- Ideal gas law calculatorPV = nRT for any variable, any unit.
- Density calculatorDensity, mass or volume; element densities.
- Chemistry tutor (AI)Ask a chemistry question and get a step-by-step explanation.
Reading the table
Each tile carries four facts. The small number is the atomic number, the count of protons that defines the element. The large letters are the symbol, fixed by IUPAC and often from Latin (Fe from ferrum, Na from natrium). Below sits the name, and on the data sheets the standard atomic weight in grams per mole.
Position tells you almost everything else. The period (row) is the number of the outermost electron shell. The group (column) sets how many electrons sit in that shell, and those outer electrons do the chemistry. That is why lithium, sodium and potassium, stacked in group 1, all fizz in water, and why neon, argon and krypton in group 18 barely react with anything.
Colour the chart by Block and the table splits into s, p, d and f regions: the subshell that the last electron enters. The shape of the periodic table is simply the shape of electron filling. The electron configuration calculator lets you step through that filling one electron at a time.
Questions students ask
How many elements are on the periodic table?
118. The last four (nihonium, moscovium, tennessine and oganesson) were officially named by IUPAC in 2016, completing period 7.
How is the periodic table organised?
Elements are placed in order of atomic number (protons in the nucleus). Rows are periods: every element in a row has the same number of occupied electron shells. Columns are groups: elements in a group have the same number of outer electrons, so they react in similar ways.
Why are the lanthanides and actinides shown separately?
They belong in periods 6 and 7 between groups 2 and 3, but putting them inline would make the table 32 columns wide. Printing them as two rows underneath keeps the chart readable. They are the f-block, where the 4f and 5f subshells fill.
What do the colours mean?
In “Category” mode each colour is a family of elements with shared chemistry (alkali metals, halogens, noble gases and so on). Switch the colour mode to see blocks, physical state at room temperature, or heat maps of electronegativity, atomic radius and ionization energy.
Which atomic masses does this table use?
Standard atomic weights as published by IUPAC, rounded to three decimals on the tiles. For radioactive elements with no stable isotope, the mass number of the longest-lived isotope is shown in brackets, e.g. [98] for technetium.
Can I use this periodic table offline or in class?
Yes. Every page is a static page, so once loaded it keeps working, and it projects well on a classroom screen. Tap any tile for its data sheet.