# Interactive Periodic Table - Atomic Mass, Electronegativity

> Interactive periodic table of all 118 elements: colour by category, block, electronegativity, atomic mass, phase or melting point; search and click for details.

- URL: https://qilingtools.com/en/math/periodic-table
- Category: Chemistry Tools (https://qilingtools.com/en/chemistry)
- Tags: [Chemistry](https://qilingtools.com/en/tags/chemistry), [Education](https://qilingtools.com/en/tags/education)
- Last updated: 2026-10-26
- Price: Free, no sign-up
- Privacy: Runs locally in the browser; files are never uploaded

This is a clickable periodic table in the standard 18-column layout, with the lanthanides and actinides in their own rows below. By default the elements are coloured by category (alkali metals, alkaline earth metals, transition metals, post-transition metals, metalloids, reactive nonmetals, halogens, noble gases, lanthanides and actinides). You can switch to s, p, d and f blocks or the phase at standard conditions, or turn Pauling electronegativity, atomic mass, melting point or boiling point into a heat map to see the periodic trends at a glance — electronegativity rising towards the top right, melting points peaking around carbon and tungsten. Click any element to see its English and Chinese names, atomic number, IUPAC standard atomic weight, group, period, block, electronegativity, electron configuration (such as [Ar] 3d⁶ 4s², including the exceptions like Cr and Cu), common oxidation states, phase and melting and boiling points in kelvin and Celsius. Search by symbol, name or atomic number; on a phone the table scrolls sideways.

## How to use

1. Choose what to colour by: category, block, electronegativity, atomic mass, phase, melting or boiling point
2. Type a symbol, name or atomic number into the search box to dim the elements that don’t match
3. Click any element for its atomic weight, electron configuration, oxidation states and melting and boiling points

## Features

- All 118 elements in the standard 18-group layout, with separate lanthanide and actinide rows
- English and Chinese element names
- Seven colour modes: category, s/p/d/f block, electronegativity, atomic mass, phase, melting and boiling point heat maps
- IUPAC standard atomic weights; radioactive elements show the most stable isotope
- Electron configurations from the Madelung rule with the measured exceptions (Cr, Cu, Pd, lanthanides, actinides…)
- Common oxidation states, Pauling electronegativity, melting and boiling points in K and °C
- Search by symbol, name or atomic number
- Scrolls sideways on small screens; tap for details

## FAQ

### How is the periodic table arranged?

Elements are ordered by atomic number, the number of protons. Each row is a period — there are seven, and the period number equals the number of electron shells. Each column is a group — there are 18 — and elements in a group have similar outer electron configurations and chemistry. The lanthanides (57–71) and actinides (89–103) sit in two rows below the main table so it doesn’t get too wide.

### What are the s, p, d and f blocks?

Blocks are named after the subshell that receives the last electron: groups 1 and 2 (plus helium) form the s-block, groups 13–18 the p-block, the transition metals in groups 3–12 the d-block, and the lanthanides and actinides the f-block. Switch the colouring to Block to see the four regions.

### What is the trend in electronegativity?

Electronegativity measures how strongly an atom attracts electrons in a bond; this table uses the Pauling scale. It increases from left to right across a period and decreases down a group, so fluorine is highest (3.98) and caesium and francium are lowest (about 0.7–0.8). Helium, neon and argon have no accepted Pauling value and are shown as unknown.

### Why are some atomic masses in square brackets?

Technetium, promethium and most elements from polonium onwards have no stable isotopes and no fixed natural isotopic composition, so they have no standard atomic weight. By convention the mass number of the longest-lived isotope is given in brackets instead — technetium [98], plutonium [244] and so on.

## Related tools

- [Significant Figures Calculator](https://qilingtools.com/en/math/significant-figures): Free online sig fig calculator: count significant figures digit by digit, round to N sig figs or decimals with six rounding modes, and compute by sig fig rules.
- [Chemical Equation Balancer](https://qilingtools.com/en/math/chemical-equation): Balance chemical equations by the algebraic method: smallest whole-number coefficients, brackets, hydrates, ionic charges, electrons, atom and charge checks.
- [Molar Mass Calculator](https://qilingtools.com/en/math/molar-mass): Molar mass of any formula with IUPAC atomic weights: brackets and hydrates, mass percent of each element, grams ↔ moles ↔ particles and solution molarity.
- [pH Calculator](https://qilingtools.com/en/math/ph): Free pH calculator for strong and weak acids and bases, polyprotic acids, salts and buffers, with an exact charge-balance solution and species plots.
- [Titration Curve](https://qilingtools.com/en/math/titration): Free acid-base titration curve simulator: exact curves for strong, weak and polyprotic acids and bases, equivalence-point pH, the jump and indicator picks.
- [Gas Law Calculator](https://qilingtools.com/en/math/gas-law): Free gas law calculator: solve PV=nRT for any variable, combined gas laws, gas density, Dalton's partial pressures, gas over water and van der Waals Z.
- [Solution & Dilution Calculator](https://qilingtools.com/en/math/solution): Free dilution calculator: solve C1V1=C2V2, convert molarity, % w/w, ppm and molality, mix solutions, plan serial dilutions and dilute stock acids.
- [Stoichiometry & Limiting Reagent](https://qilingtools.com/en/math/stoichiometry): Balances the equation, finds the limiting reactant from grams, moles, gas volume or molarity, and gives theoretical yield, excess and percent yield with steps.