Difference Between — Science Comparisons
The exam favourite "distinguish between" questions, answered clearly. Side-by-side comparison tables for Class 11 & 12 Physics, Chemistry, Biology and Maths — each with a one-line answer, a full table, and FAQs.
⚛️ Physics
Speed vs Velocity
Speed is a scalar quantity that measures how fast an object moves (magnitude only); velocity is a vector quantity that measures how fast and in which direction it moves.
See the difference → ⚛️ PhysicsDistance vs Displacement
Distance is the total length of the path travelled (scalar, always positive); displacement is the shortest straight-line distance from start to end, with direction (vector).
See the difference → ⚛️ PhysicsMass vs Weight
Mass is the amount of matter in an object (scalar, constant everywhere, measured in kg); weight is the gravitational force on that mass (vector, changes with g, measured in newtons).
See the difference → ⚛️ PhysicsScalar vs Vector
A scalar has only magnitude (e.g. mass, speed, temperature); a vector has both magnitude and direction (e.g. velocity, force, displacement).
See the difference → ⚛️ PhysicsAC (Alternating Current) vs DC (Direct Current)
Alternating current (AC) periodically reverses its direction and is used for power transmission; direct current (DC) flows steadily in one direction and is used in batteries and electronics.
See the difference →🧪 Chemistry
Ionic Bond vs Covalent Bond
An ionic bond forms by the complete transfer of electrons from a metal to a non-metal (creating ions); a covalent bond forms by the sharing of electron pairs between non-metals.
See the difference → 🧪 ChemistrySigma (σ) Bond vs Pi (π) Bond
A sigma (σ) bond forms by head-on (axial) overlap of orbitals and is stronger; a pi (π) bond forms by sideways (lateral) overlap of p-orbitals and is weaker.
See the difference → 🧪 ChemistryOxidation vs Reduction
Oxidation is the loss of electrons (or gain of oxygen / loss of hydrogen); reduction is the gain of electrons (or loss of oxygen / gain of hydrogen).
See the difference → 🧪 ChemistryAldehyde vs Ketone
In aldehydes the carbonyl carbon is bonded to at least one hydrogen and sits at the end of the chain (–CHO); in ketones the carbonyl carbon is bonded to two carbon atoms and sits within the chain.
See the difference → 🧪 ChemistryEndothermic Reaction vs Exothermic Reaction
Endothermic reactions absorb heat from the surroundings (ΔH is positive, surroundings cool); exothermic reactions release heat to the surroundings (ΔH is negative, surroundings warm).
See the difference →🔬 Biology
Mitosis vs Meiosis
Mitosis produces 2 genetically identical diploid cells for growth and repair, while meiosis produces 4 genetically different haploid cells (gametes) for sexual reproduction.
See the difference → 🔬 BiologyDNA vs RNA
DNA is a double-stranded molecule with deoxyribose sugar and the base thymine that stores genetic information; RNA is usually single-stranded with ribose sugar and the base uracil, and carries out protein synthesis.
See the difference → 🔬 BiologyProkaryotic Cell vs Eukaryotic Cell
Prokaryotic cells have no membrane-bound nucleus or organelles and are small (1–10 μm), while eukaryotic cells have a true nucleus and membrane-bound organelles and are larger (10–100 μm).
See the difference → 🔬 BiologyPlant Cell vs Animal Cell
Plant cells have a cellulose cell wall, chloroplasts and a large central vacuole; animal cells lack these but have centrioles and only small vacuoles.
See the difference → 🔬 BiologyArtery vs Vein
Arteries carry blood away from the heart under high pressure and have thick muscular walls; veins carry blood towards the heart under low pressure, have thinner walls and valves to prevent backflow.
See the difference → 🔬 BiologyXylem vs Phloem
Xylem transports water and minerals from roots to leaves through mostly dead cells (one direction, upward); phloem transports food (sugars) throughout the plant through living cells (both directions).
See the difference →