Master Chemistry Fundamentals Through Interactive Learning
Learn atoms, bonding, the periodic table, reactions, stoichiometry, acids and bases, equilibrium, and more through clear explanations, shown-working calculators, visual models, and targeted practice.
- ✓ Free core learning
- ✓ Calculators without login
- ✓ Sources & review dates
- ✓ Step-by-step working
Notebook visual — not a stock illustration. Lightweight inline SVG, no extra requests.
Platform statistics
Choose your starting point
Pick the path that fits you — we’ll keep you on a clear, reviewed route.
I’m new to chemistry
Start from zero with foundations and measurement.
High-school chemistry
Aligned to core curriculum and exam prep.
Introductory college chemistry
General Chemistry I/II with problem sets.
I need a calculator
Jump straight to verified tools with shown working.
I want practice questions
Quizzes, flashcards, and daily challenges.
I’m a teacher
Printables, question sets, and classroom resources.
Core topic map
16 topics • concise, reviewed lessonsMatter and Measurement
Units, significant figures, and classifying matter.
ExploreAtomic Structure
Protons, neutrons, electrons, isotopes, and orbitals.
Periodic Table and Trends
Periodicity, radii, ionisation, and electronegativity.
ExploreChemical Bonding and Molecular Shape
Lewis, VSEPR, polarity, and intermolecular forces.
ExploreNaming, Formulas, and Compounds
Ionic and covalent nomenclature and composition.
ExploreChemical Reactions and Equations
Balancing, types, and conservation of mass.
ExploreMole and Stoichiometry
Avogadro, limiting reactant, and percent yield.
ExploreStates of Matter and Gas Laws
Gases, liquids, solids, and combined gas law.
ExploreSolutions and Concentration
Molarity, dilution, and solubility.
ExploreAcids, Bases, and Buffers
pH, pOH, Ka, buffers, and titrations.
ExploreThermochemistry and Thermodynamics
Enthalpy, entropy, Gibbs, and Hess.
ExploreKinetics and Equilibrium
Rate laws, mechanisms, Keq, and Le Châtelier.
ExploreRedox and Electrochemistry
Oxidation states, galvanic and electrolytic cells.
ExploreOrganic Chemistry Foundations
Hydrocarbons, functional groups, and isomerism.
ExploreNuclear Chemistry
Decay modes, half-life, and binding energy.
ExploreLaboratory Skills and Safety
Techniques, PPE, and hazard management.
ExplorePopular calculators
All calculators →Each tool shows formula, inputs, outputs, and step-by-step working — no black boxes.
Molar Mass
M = Σ ArCompute molecular weight from formula.
Equation Balancer
aA + bB → cCBalance equations with conservation table.
Grams and Moles
n = m / MConvert mass ↔ amount with Avogadro.
Stoichiometry
m = n·MLimiting reactant and theoretical yield.
Molarity
c = n / VConcentration and dilution.
pH and pOH
pH = −log[H⁺]Acid–base strength from [H⁺] / [OH⁻].
Limiting Reactant
n / νIdentify excess and limiting reagents.
Ideal Gas Law
PV = nRTPV = nRT with unit handling.
Interactive periodic-table preview
Search, filter by category, and explore trends — then open the full table. Accessible list alternative on mobile.
Mobile: swipe the preview — or use the list view.
Oxygen
Nonmetal • Group 16 • Period 2
- Electron config
- [He] 2s² 2p⁴
- Electronegativity
- 3.44 (Pauling)
- Category
- Reactive nonmetal
- State at STP
- Gas
Hover or focus an element — details appear here with keyboard support.
View element page →Chemistry Fundamentals from Zero
For first-time learners — matter, atoms, bonding, reactions, and quantitative chemistry in a sequenced route with checks and practice.
- Level
- Beginner
- Modules
- 12 modules
- Time
- ~28 hrs
- Prerequisites
- None
- 1 Foundations & measurement — units, matter, uncertainty
- 2 Atomic structure — isotopes, orbitals, electron config
- 3 Bonding & shape — Lewis, VSEPR, polarity
- 4 Reactions & stoichiometry — balancing, mole, yield…
What you’ll be able to do
- ✓ Convert units and handle significant figures
- ✓ Draw Lewis structures and predict shapes
- ✓ Balance equations and do stoichiometry
- ✓ Relate pH, concentration, and equilibrium
Practice and simulations
Hands-on — build, balance, and test understanding with instant feedback that explains misconceptions.
Balance the Equation
Drag coefficients — conservation table checks each step.
Build an Atom
Add protons, neutrons, electrons — see charge and mass.
Periodic Table Challenge
Timed recall of symbols, groups, and trends.
VSEPR Shape Builder
Place electron pairs — geometry and polarity appear.
Titration Curve Lab
Add titrant, watch pH, find equivalence.
Stoichiometry Sprint
Mole bridges under time — with full working.
How learning works
Understand
Clear explanations with objectives, prerequisites, and misconceptions.
Visualize
Particle diagrams, trend charts, and molecular models.
Calculate
Formulas with variables, units, and shown working.
Practice
Checks, worked examples, and spaced repetition.
Latest reviewed lessons
All lessons →Balancing Chemical Equations — Conservation of Atoms and Charge
How to balance chemical equations by inspection while conserving atoms and charge, with a conserved-atom table and common-subscript pitfall.
Mole and Avogadro Constant — Amount of Substance
Amount of substance (mol) as counting unit for entities; Avogadro constant NA = 6.02214076×10²³ mol⁻¹ exactly, and its use in mass↔entity conversions.
pH and pOH
Use logarithms to move between hydrogen-ion concentration, hydroxide concentration, pH, and pOH.
Scientific standards and trust
We show sources, review dates, and calculation assumptions. Corrections are logged openly — see our policies.
- ✓ Sources cited with access dates and versions
- ✓ Calculations reviewed and approximation labels shown
- ✓ Reviewer attribution on every published lesson
- ✓ Public correction log
How we handle uncertainty
- Approximations labelled
- e.g., ideal gas, dilute solutions — assumptions shown before results.
- Data versions
- Periodic data versioned (NIST, IUPAC) with last-reviewed stamps.
- Report a correction
- Contact us — we fix and note it.
Teacher resources
Classroom-safe, printable, and free to use.
FAQ
Is the site free?
Yes — core lessons and all calculators are free and work without login. Saved items and progress are stored on your device.
What levels are covered?
Foundations through introductory college (General Chemistry I/II). High-school paths are aligned to common curricula.
Do calculators show working?
Every result includes the formula, substituted values, units, and assumptions — so you can learn, not just copy.
Where does scientific data come from?
Periodic and constant data are sourced from NIST and IUPAC with version and access dates. Each page lists its references.
Can teachers use the resources?
Absolutely — printables, question sets, and charts are prepared for classroom use. See Teacher resources above.
Is an account required?
No. All learning and calculators work without an account. Any saved items stay in your browser.