Periodic Table — Interactive Element Explorer
Click any element to see its atomic number, symbol, name, atomic mass, and category. Filter by element type to highlight groups like noble gases, transition metals, or lanthanides. No signup, runs entirely in your browser.
How to Use the Interactive Periodic Table
- 1Click any element to see its atomic number, symbol, name, atomic mass, and category.
- 2Use the category filter to highlight one group — noble gases, halogens, transition metals, and so on.
- 3Read position as information: a period (row) adds an electron shell; a group (column) shares valence electrons.
- 4Trace periodic trends visually across rows and down columns.
Worked Example: Reading Why Sodium Is So Reactive
Click sodium (Na, Z = 11). It sits in Group 1, the alkali metals, on the far left of period 3. Group 1 tells you it has a single valence electron, and being low in the group means that electron is far from the nucleus and loosely held. That is the whole story of sodium's violent reaction with water: it readily gives up that one electron to form Na⁺. Highlight the Group 1 filter and you see the same pattern intensify downward — potassium reacts harder than sodium, caesium harder still.
Now jump to the opposite corner and click a noble gas like neon (Ne, Z = 10) in Group 18. Its outer shell is full, so it has almost no tendency to react — the reason neon glows harmlessly in signs while sodium must be stored under oil. The table's layout is the explanation: reactivity, atomic radius, and ionisation energy all trend predictably by position, so knowing where an element sits tells you how it behaves before you look up a single reaction.
Periodic Table Tips
Use the category filter
Click any category button above the table to dim all other elements and highlight the group you are studying. Noble gases, halogens, and alkali metals are common exam questions.
Periodic trends
Atomic radius increases down a group and decreases left to right across a period. Electronegativity and ionisation energy show the opposite trend. These trends are visible directly in the table layout.
Memorise key elements
Focus on elements 1-20 for most school exams. The symbols for transition metals (Fe=Iron, Cu=Copper, Ag=Silver, Au=Gold, Hg=Mercury) are the most commonly confused because they come from Latin names.
f-block rows
Lanthanides and actinides are placed below the main table for space, but they belong in periods 6 and 7. La (Z=57) and Ac (Z=89) mark where each f-block row connects back to the main table.
Frequently Asked Questions
How many elements are in the periodic table?
The modern periodic table contains 118 confirmed elements, from Hydrogen (Z=1) to Oganesson (Z=118). Elements 1-94 occur naturally; elements 95-118 are synthetic (produced in laboratories).
What do the colours represent?
Elements are colour-coded by category: alkali metals, alkaline earth metals, transition metals, post-transition metals, metalloids, reactive nonmetals, halogens, noble gases, lanthanides, and actinides. Use the "Highlight" filter to isolate any category.
What is atomic mass?
Atomic mass (shown in atomic mass units, u) is the weighted average mass of all naturally occurring isotopes of an element. For synthetic elements, the mass shown is the most stable isotope (no stable isotopes exist for these elements).
What are lanthanides and actinides?
Lanthanides (La to Lu, Z=57-71) are the f-block elements in period 6. Actinides (Ac to Lr, Z=89-103) are the f-block elements in period 7. They are placed in separate rows below the main table because their chemical behaviour differs from the d-block transition metals.
What is a period and a group?
A period is a horizontal row in the periodic table — each period adds one electron shell. A group (or family) is a vertical column — elements in the same group have the same number of valence electrons and similar chemical properties.
Is my data stored?
No. The periodic table is fully static data loaded in your browser. No information is sent to any server.