Et

Chemistra

Explore the elements · 118

118

Periodic grid

tap a tile · zoom or families for bigger taps

1234567891011121314151617181234567

Filter by family

Specimen browser

118 of 118

Periodic trends

Atomic radius across period 3(pm)

NaMgAlSiPSClAr

Atoms shrink left to right: the growing nuclear charge pulls the same shell in tighter.

Quiz LabElements & formulas, timed📐Formula FinderClass 6 → college, in orderFormula VaultDerivations, units and worked exam questions📘Physics FormulaeMotion → modern physics🧮Physics SolverFind the missing value📗Maths FormulaeArithmetic → calculus⏱️Tables & Drill60 seconds of mental mathsMass WizardAny element or compound, with breakdown and grams → molesTrend TrackerPauling values, bond type and ionic characterδ−Reactivity LadderMetals, halogens, displacement and extraction rulesAcid InsightspKa, Ka, conjugate bases and why an acid is strongpHVoltage ChartE° half-cells, cell emf and ΔG° in one searchReduction MapE°red and E°ox for every half-cell, strongest to weakest⇩eSalt DecoderFormulas, ion charges, solubility rules, colours and tests