Science class - Free chemistry and physics lessons ressources

This free website will help you to enrich your learning in science. It provides free science online ressources for kids, students, beginners, parents looking for homeworks help and everyone curious about physics and chemistry. It can be useful for self studying, to review lessons, to prepare for science exams, for learning scientific basis and even for school projects.
All learners can access without restriction to science lessons in various fields such as chemistry, electricity, optics or mechanics written with scientific rigor. Most of these lessons, written with simple words, include basics notions making them understandable by everyone.

Chemistry lessons
Water, states of matter, atom, molecule, chemical reaction, ion, combustion, metal ...

Electricity lessons
Electric circuit, current, conductor, insulator, Ohm's law, series and parallel circuit, circuit diagram ...

Mechanics lessons
motion, speed, trajectory, mass, weight, rotation, kinetic energy, Isaac Newton ...

Optics lessons
Light, laser, shadow, propagation of light, ray, converging and diverging lens, color ...


Chemistry Water Water on Earth Changes of state in the nature: the water cycle Water in human body Test for water Properties of water in different states States of matter States of matter and its changes Boiling water Water: freezing and melting Changes of state: mass and volume Molecules in different states of matter Mixtures and solutions Heterogeneous mixtures Homogeneous mixtures Decantation Centrifugation Filtration Vaporization of water Distillation Chromatography Dissolving a solid in water Conservation of mass on dissolving Miscibility in water Mass and volume Volume and its units Measuring volume with a graduated cylinder Mass and its units Measuring the mass of a liquid Mass of a liter of water Air and atmosphere Atmosphere Earth's atmosphere protect us Threats to the Earth's atmosphere Composition of air Air and life Pressure Atoms and molecules Molecules Molecules in mixtures and pure substances Molecules and states of matter Atoms Composition of molecules Constituents of the atoms The electrical neutrality of the atom Combustions Basics of combustion The combustion of carbon The combustion of butane Atoms and chemical reactions Chemical reactions Chemical equations Law of conservation of mass Chemical synthesis Metals Most common metals How to distinguish metals ? Corrosion of metals Electrical conductivity of solid materials Electrons and free electrons Electric current in metals Ions The conductivity of aqueous solutions Aqueous solutions and ions The direction of movement of ions Formation of ions Tests for ions Acidic and basic solutions pH of aqueous solutions Ions in acidic and basic solutions Dilution of acids and bases Composition of hydrochloric acid Chemical reaction between iron and hydrochloric acid Electrochemical cells and chemical energy Chemical reaction beteween a copper sulphate solution and zinc Copper sulfate and zinc battery Basics of electrochemical cell	Electricity (Soon) Electrical components Two-terminal electronic components Basic electrical components Diodes What's a resistor ? How to determine a resistor value ? Resistors effects in circuits How to use a resistor ? Characteristic curve of a resistor How to build simple circuits and draw diagrams How to build a basic electrical circuit How to draw diagrams of electric circuits The electric current Conductors and insulators Direction of electric current in a circuit The dangers of electricity Current intensity - units how to measure current ? The Voltage The voltage and its units How to measure a voltage ? Voltage in open and closed circuits Rated current and voltage for a lamp Alternating voltage and current Alternating currents effects on led What are alternating current and voltage ? Periodic alternating voltage and its properties Oscilloscope Oscillogram Frequency Measuring RMS voltage with a voltmeter Serie circuits What's a serie circuit ? Series circuit properties Short circuit in series circuit Current law in series circuits Voltage law in series circuits Parallel circuits What's a parallel circuit ? Some parallel circuits properties Short circuits in parallel circuits Nodes and branches in parallel circuits Current laws in parallel circuits Voltage laws in parallel circuits Laws of electricity Ohm's law Current laws in series circuits Voltage laws in series circuits Current laws in parallel circuits Voltage laws in parallel circuits Generating electricity Voltage for coil wires What is an alternator ? Alternating currents and voltages Generating electricity in power plants Electric power and energy Electric power and power rating Electric power received by an electrical device Electric power consumption by an electrical device Relationship between Electric power and energy	Optics Light sources Types of light sources Why can we see objects ? Propagation of light Rectilinear propagation of light beams of light Speed of light Light and distances Shadows, lunar eclipses and phases of the moon Formation of shadows The Moon and eclipses Colored lights - color of objects Decomposition of white light Colored lights Color of objects Image formation - Thin lenses Thin converging and diverging lenses Image formation by thin lenses Vision and eyes	Mechanics Gravity The solar system - motions of celestial bodies Physical interactions Effects of gravity Weight of an object Difference between weight and mass Relationship between weight and mass Energy Energy basics Potential energy Kinetic energy Mechanical energy Translational Kinetic Energy kinetic energy mass and speed