Tamil Nadu SSLC Science flashcards
Tamil Nadu SSLC Science · Build recall with a focused review session.
33 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Newton's second law
- The net force on a body equals mass times acceleration, F = ma. Acceleration is in the direction of the net force and is inversely proportional to the mass.
- Conservation of momentum
- When no net external force acts, the total momentum of a system before a collision equals the total after. This explains recoil and rocket motion.
- Static friction
- The self-adjusting force that prevents a stationary body from sliding. It increases up to a maximum value μsN and then gives way to kinetic friction.
- Snell's law
- For light crossing a boundary, n₁ sin i = n₂ sin r. The ratio of the sines of incidence and refraction angles is constant for a given pair of media.
- Total internal reflection
- Occurs when light travels from a denser to a rarer medium at an angle greater than the critical angle C, where sin C = 1/n. The light reflects fully.
- Lens power
- The reciprocal of focal length in metres, P = 1/f, measured in dioptres. A converging convex lens has positive power; a diverging concave lens has negative power.
- Ohm's law
- At constant temperature, the current through a conductor is directly proportional to the potential difference across it, so V = IR, where R is resistance.
- Resistance in parallel
- The reciprocal of the total resistance equals the sum of the reciprocals of individual resistances. All branches share the same voltage but carry different currents.
- Fleming's left-hand rule
- With thumb, forefinger and middle finger mutually perpendicular, they give the force, magnetic field and current directions for a current-carrying conductor in a magnetic field.
- Electromagnetic induction
- A changing magnetic flux linked with a coil induces an emf in it. This principle underlies generators and transformers and was described by Faraday.
- Modern periodic law
- Properties of elements are periodic functions of their atomic number. Elements are arranged in increasing atomic number across seven periods and eighteen groups.
- Ionisation energy trend
- Ionisation energy increases across a period as nuclear charge grows and radius shrinks, and decreases down a group as the outer electron is farther and shielded.
- Halogen reactivity
- Halogens form −1 ions and are strong oxidising agents. Reactivity and electronegativity decrease down Group 17 from fluorine to iodine.
- Ionic bond
- Formed by complete transfer of electrons from a metal atom to a non-metal atom, producing oppositely charged ions held by strong electrostatic attraction in a lattice.
- Covalent bond
- Formed by sharing of electron pairs between non-metal atoms. The shared pair is attracted by both nuclei, giving molecules with low melting points and poor conductivity.
- Coordinate bond
- A covalent bond in which one atom donates both electrons of the shared pair, as in the ammonium ion NH₄⁺ and the hydronium ion H₃O⁺.
- pH scale
- A measure of hydrogen ion concentration, pH = −log[H⁺]. Values below 7 are acidic, 7 is neutral and above 7 basic at 25 °C.
- Neutralisation reaction
- An acid reacts with a base to form salt and water. For example, hydrochloric acid with sodium hydroxide gives sodium chloride and water.
- Water of crystallisation
- Fixed number of water molecules chemically combined in one formula unit of a hydrated salt, as in blue CuSO₄·5H₂O, which turns white on heating.
- Catenation
- The ability of carbon atoms to link with one another forming long chains, branches and rings. It accounts for the very large number of carbon compounds.
- Homologous series
- A family of organic compounds with the same general formula and functional group, differing by one CH₂ unit, showing graded physical and similar chemical properties.
- Esterification
- A carboxylic acid reacts with an alcohol in the presence of an acid catalyst to form an ester and water. Esters have sweet smells used in flavours.
- Mitochondrion
- A double-membraned organelle where aerobic respiration occurs. It releases energy as ATP and is therefore called the powerhouse of the cell.
- Osmosis
- Movement of water across a selectively permeable membrane from a region of lower solute concentration to higher solute concentration, without external energy input.
- Prokaryotic cell
- A cell lacking a membrane-bound nucleus and organelles, such as a bacterium. Its genetic material lies free in the cytoplasm as a single circular DNA molecule.
- Photosynthesis
- Green plants use light energy to convert carbon dioxide and water into glucose and oxygen in chloroplasts, with chlorophyll absorbing the light.
- Transpiration
- Loss of water vapour from leaves through stomata. It creates a pull that draws water and minerals upward through the xylem.
- Nephron
- The functional unit of the kidney. It filters blood in the glomerulus and reabsorbs useful substances in the tubule, forming urine.
- Law of segregation
- Mendel's principle that the two alleles of a gene separate during gamete formation, so each gamete receives only one allele of each pair.
- Natural selection
- Darwin's mechanism of evolution: individuals with favourable variations survive and reproduce more, passing those traits to later generations.
- Ten percent law
- Only about ten percent of energy at one trophic level is transferred to the next. The rest is lost as heat, limiting food chain length.
- Acquired immunity
- Specific defence developed after exposure to a pathogen or vaccine, involving antibodies and memory cells that give a faster response on later exposure.
- Least count
- The smallest measurement an instrument can read. For vernier callipers it is usually 0.1 mm; for a screw gauge it is 0.01 mm.