Here’s a glossary of Science terms and abbreviations, covering general science, physics, chemistry, biology, earth sciences, and modern technology concepts. This is designed as a master reference for students, enthusiasts, and educators.
🔬 SCIENCE GLOSSARY
A
Acceleration (a) – Rate of change of velocity per unit time.
Acid – Substance with pH < 7, donates hydrogen ions (H⁺).
Alkali / Base – Substance with pH > 7, accepts hydrogen ions or donates OH⁻.
Atom – Basic unit of matter consisting of protons, neutrons, and electrons.
Allele – Variant form of a gene.
Astronomy – Study of celestial objects and the universe.
ATP (Adenosine Triphosphate) – Energy-carrying molecule in cells.
B
Bacteria – Single-celled microorganisms, some beneficial, some pathogenic.
Biology – Study of living organisms.
Biodiversity – Variety of life in an ecosystem.
Boiling Point – Temperature at which a liquid becomes a gas.
Buoyancy – Upward force exerted by fluid on an object.
Biosphere – Regions of Earth supporting life.
C
Cell – Basic structural and functional unit of life.
Catalyst – Substance increasing reaction rate without being consumed.
Circuit – Path for electric current.
Chemical Bond – Force holding atoms together (ionic, covalent, metallic).
Chromosome – DNA-protein structure containing genetic information.
Climate – Long-term weather patterns in a region.
Conservation – Protection and management of natural resources.
D
DNA (Deoxyribonucleic Acid) – Molecule carrying genetic instructions.
Diffusion – Movement of particles from high to low concentration.
Density – Mass per unit volume.
Dipole – Separation of positive and negative charges.
Doppler Effect – Change in frequency due to motion of source or observer.
E
Ecosystem – Community of organisms interacting with their environment.
Electron – Negatively charged subatomic particle.
Energy – Capacity to do work, exists in kinetic, potential, thermal, chemical forms.
Entrophy (S) – Measure of disorder in a system.
Evolution – Change in species over generations.
Exoplanet – Planet orbiting a star outside our solar system.
F
Force (F) – Interaction causing a change in motion (F = ma).
Frequency (f) – Number of cycles per second (Hz).
Fossil – Preserved remains or traces of ancient organisms.
Freezing Point – Temperature at which liquid becomes solid.
Fusion / Fission – Nuclear reactions releasing energy; fusion combines nuclei, fission splits them.
G
Gene – Unit of heredity determining traits.
Genome – Complete set of genetic material in an organism.
Gravity (g) – Force of attraction between masses.
Greenhouse Effect – Trapping of heat by gases in atmosphere.
H
Half-Life – Time for half of radioactive substance to decay.
Hydrogen Bond – Weak bond between hydrogen and electronegative atom.
Hypothesis – Proposed explanation based on limited evidence.
Homeostasis – Maintenance of stable internal conditions in organisms.
I
Ion – Atom or molecule with electric charge due to electron gain/loss.
Isotope – Atoms of same element with different neutron numbers.
Immunity – Ability to resist disease.
Inertia – Tendency of an object to resist changes in motion.
Igneous Rock – Formed by cooling of magma or lava.
J
Joule (J) – Unit of energy.
Jet Stream – Fast-flowing narrow air currents in atmosphere.
K
Kinetic Energy – Energy of motion (KE = ½ mv²).
Kelvin (K) – SI unit of temperature.
Keystone Species – Species critical to ecosystem structure.
L
Light Year – Distance light travels in one year (~9.46 × 10¹² km).
Ligand – Molecule binding to a central atom in chemistry or biochemistry.
Luminosity – Intrinsic brightness of a star or celestial object.
Law of Conservation of Energy – Energy cannot be created or destroyed, only transformed.
M
Matter – Anything with mass and volume.
Molecule – Two or more atoms bonded together.
Magnetism – Force of attraction or repulsion due to magnetic fields.
Momentum (p) – Mass × velocity, conserved in closed systems.
Mutation – Change in DNA sequence.
N
Neuron – Nerve cell transmitting electrical impulses.
Newton (N) – Unit of force.
Nucleus – Core of an atom containing protons and neutrons; also cell organelle.
Natural Selection – Mechanism of evolution favoring traits increasing survival.
Nanotechnology – Science of manipulating matter at atomic/molecular scale.
O
Oxidation – Loss of electrons in chemical reaction.
Osmosis – Diffusion of water through a semipermeable membrane.
Organism – Living individual.
Optics – Study of light behavior.
Ozone Layer – Stratospheric layer absorbing UV radiation.
P
Photosynthesis – Process plants use to convert sunlight into chemical energy.
pH Scale – Measure of acidity/alkalinity (0–14).
Plate Tectonics – Movement of Earth's lithospheric plates.
Photon – Quantum of light or electromagnetic radiation.
Pressure (P) – Force per unit area (Pa).
Protein – Macromolecule composed of amino acids; essential for life.
Q
Quantum Mechanics – Physics of subatomic particles.
Quark – Fundamental particle composing protons and neutrons.
Quasar – Extremely luminous active galactic nucleus.
R
Radioactivity – Emission of particles/radiation by unstable nuclei.
Refraction – Bending of light as it passes through different media.
Respiration – Process by which organisms release energy from food.
RNA (Ribonucleic Acid) – Nucleic acid involved in protein synthesis.
Renewable Energy – Energy from sources naturally replenished.
S
Solar System – Sun and all celestial bodies orbiting it.
Static Electricity – Accumulation of electric charge on surfaces.
Subatomic Particle – Particle smaller than atom (electron, proton, neutron).
Supernova – Explosive death of a massive star.
Saturated Solution – Maximum solute dissolved in solvent at a given temperature.
T
Thermodynamics – Study of energy, heat, and work.
Transpiration – Water loss from plants through leaves.
Tectonic Plate – Section of Earth's lithosphere.
Tissue – Group of similar cells performing a function.
U
Universe – All of space, time, matter, and energy.
Ultraviolet (UV) Radiation – Electromagnetic radiation with wavelength shorter than visible light.
Unicellular / Multicellular – Organisms with one or many cells.
Ubiquitin – Protein involved in tagging other proteins for degradation.
V
Velocity (v) – Speed with direction.
Viscosity – Resistance of fluid to flow.
Volcano – Geological formation where magma erupts.
Vapor Pressure – Pressure exerted by a vapor in equilibrium with liquid.
W
Wavelength (λ) – Distance between successive peaks of a wave.
Work (W) – Energy transferred by a force acting over distance (W = F × d).
Wave-Particle Duality – Concept that particles like photons exhibit wave-like behavior.
Watts (W) – Unit of power.
X
X-Ray – High-energy electromagnetic radiation.
Xylem – Plant tissue transporting water from roots to leaves.
Y
Yield / Reaction Yield – Amount of product from chemical reaction.
Yolk – Nutrient-rich part of an egg.
Z
Zoology – Study of animals.
Zero Point Energy – Minimum quantum energy of a system.
Zeolite – Mineral used in filtration, catalysis, and water purification.
Published 17th Feb 2026