- Saturated Solution
- (n.) A solution in which no more solute can be dissolved.
- Season
- (n.) A phenomenon that lasts approximately three months in France and is characterized by the heights reached by the Sun above the horizon. There are four seasons in France: winter, spring, summer, and autumn.
- Self Shadow
- (n.) Unlit area on the surface of an object that receives light.
- Series Circuit
- (n.) Electrical circuit in which components are connected one after the other. A series circuit has only one electrical path. In a series circuit, if one component fails, the other components do not function.
- Shadow Cone
- (n.) Part of space located behind an opaque object illuminated by a point light source that does not receive light from the source.
- Shadow
- (n.) Area that does not receive light.
- Short Circuit
- (n.) Accidental contact between two terminals of a two-terminal component using a good electrical conductor (often copper wire, a piece of iron, or carbon). If the component is a generator, this situation results in a very intense electrical current that can cause the conductors to overheat, possibly leading to the combustion of insulators or even a fire.
- Silver nitrate
- (n.m.) A colorless solution with the formula (Ag+ + NO3-) used to identify chloride ions Cl-. In the presence of chloride ions Cl-, the silver nitrate solution produces a white precipitate of silver chloride (AgCl).
- Sinusoidal Voltage
- (n.) Periodic alternating voltage whose graphical representation is a sine wave.
- Smoke
- (n.) A collection of fine solid particles and liquid droplets suspended in the air.
- Sodium Hydroxide (Caustic Soda)
- (n.) A solution of sodium hydroxide with the formula (Na+ + HO-). It is a basic solution. It attacks zinc and aluminum. It is used to identify the following ions: copper ions Cu2+, iron(II) ions Fe2+, iron(III) ions Fe3+, zinc ions Zn2+, and aluminum ions Al3+.
- Solar System
- (n.) A system comprising the Sun at the center, eight planets, thousands of asteroids, comets, meteorites, and interplanetary dust.
- Solid State
- (n.) A compact and ordered state of matter.
- Solidification
- (n.) The process of transitioning from a liquid state to a solid state.
- Soluble
- (adj.) Capable of forming a homogeneous mixture when dispersed in a liquid.
- Solute
- (n.) A substance (solid, liquid, or gas) dissolved in a solvent.
- Solution
- (n.) A liquid or solid consisting of a solute and a solvent.
- Solvent
- (n.) A liquid that can dissolve a substance.
- Spectrum
- (n.) The set of colored lights that compose a light.
- Speed of Light
- (n.f.) Ratio of the distance traveled by light to the time taken to travel that distance. The speed of light depends on the transparent medium. In a vacuum, it is equal to 300,000 km/s.
- Star
- (n.) A celestial object that emits its own light (primary source). The Sun is a star. The closest star to Earth after the Sun is Alpha Centauri, located 4.3 light-years away. Stars come in a sequence of colors: red, yellow, white, and finally blue. The coolest stars are red with a surface temperature of about 3,000°C. The hottest stars are blue with a surface temperature of about 20,000°C. The yellow surface temperature of the Sun reveals a temperature close to 6,000°C. Stars are distinguished by their mass, color, and size. The largest are called supergiants and can be up to a few thousand times the size of our Sun. The smallest, brown dwarfs, are barely larger than Jupiter.
- State of Matter
- (n.) The manner in which a substance exists. There are three states: liquid, solid, and gaseous.
- Steel
- (n.) (from the Latin acies meaning edge) Iron combined with a small amount of carbon, obtained by smelting, and capable of becoming very hard through quenching. Mild steel is a type of steel with a very low carbon content. Stainless steel is a steel containing chromium. High-speed steel is a very hard steel containing tungsten, chromium, vanadium, and molybdenum, used for making tools. Special steel is an alloy of iron and other metals.
- Sun
- (n.) The star that is the center of the solar system.
- Switch
- (noun) Electrical component that controls the flow of electric current.
- Synthesize
- (v.) To perform a chemical synthesis.