130 Essential Science Words That Start With N (With Meanings)

Science is full of interesting words, and many of them begin with the letter N. This guide explores 130 science words that start with N with clear meanings and examples. Learning these terms helps students, teachers, and science lovers build strong vocabulary. Whether you study biology, physics, chemistry, or earth science, you will discover how important “N words” are in every subject.

From the nucleus in biology to Newton’s law of motion, these words connect big ideas in science. Each section gives you definitions, examples, and explanations that make the terms easier to understand. You will also see tables and simple examples that highlight how these words are used in different fields of study.

Biology (N Words in Biology)

Word	Meaning	Example
Nucleus	Control center of a cell	The nucleus in biology stores DNA
Neuron	Nerve cell that transmits signals	A neuron definition science is vital for the nervous system
Nucleic Acid	DNA or RNA molecules	Nucleic acid meaning is genetic material
Niche	Role of an organism in its environment	The niche in biology shows where a species fits
Nervous System	Network of nerves that control actions	The brain and spinal cord form the nervous system
Nephron	Functional unit of the kidney	The nephron function filters blood
Nucleotide	Building block of DNA and RNA	Nucleotide definition is a molecule of genetic code
Natural Selection	Process where best traits survive	Natural selection biology explains evolution
Nasal Cavity	Passage inside the nose	The nasal cavity function filters air
Nitrogen Cycle	Movement of nitrogen through ecosystems	Plants absorb nitrogen in the nitrogen cycle

Physics (N Words in Physics)

Word	Meaning	Example
Newton’s Law of Motion	Rules that describe motion	Newton’s law of motion explains force and inertia
Newton	Unit of force	One Newton unit of force moves 1 kg by 1 m/s²
Neutron	Neutral particle in the nucleus	A neutron particle has no charge
Nuclear Energy	Energy from splitting atoms	Nuclear energy definition powers reactors
Nuclear Fusion	Atoms joining to release energy	Stars shine through nuclear fusion
Nuclear Fission	Atoms splitting to release energy	Reactors use nuclear fission
Nuclear Physics	Study of atomic nuclei	Nuclear physics explores atomic reactions
Normal Force	Force perpendicular to surfaces	Books rest due to normal force in physics
Nanotechnology	Study of very small particles	Nanotechnology physics makes tiny devices
Nonlinear Motion	Movement along curved paths	A planet follows nonlinear motion

Chemistry (N Words in Chemistry)

Word	Meaning	Example
Nitrogen	Element in the air	The nitrogen element makes up 78% of air
Nitric Acid	Strong acid used in labs	Nitric acid definition is HNO₃
Neutralization	Reaction of acid and base	A neutralization reaction makes salt and water
Noble Gases	Unreactive elements in group 18	Noble gases chemistry includes helium and neon
Nonmetals	Elements that lack metallic traits	Carbon and oxygen are nonmetal elements
Nucleophile	Species that donates electrons	A nucleophile chemistry attacks an atom
Nitrite	Compound with NO₂⁻	Soil may contain nitrite and nitrate
Nitrate	Compound with NO₃⁻	Plants need nitrate in soil
Nanomaterials	Substances made at nanoscale	Nanomaterials have unique properties
Nonpolar Bond	Chemical bond with equal sharing	O₂ is a nonpolar bond molecule

Earth & Space Science (N Words in Earth Science)

Word	Meaning	Example
Nebula	Gas cloud in space	A nebula astronomy makes stars
North Pole	Earth’s northernmost point	The north pole science is icy
Northern Hemisphere	Top half of Earth	Summer comes in the northern hemisphere definition
Natural Resources	Materials from Earth	Natural resources earth science include water and soil
Natural Gas	Fossil fuel for energy	Homes use natural gas for heating
Nitrate in Soil	Compound plants absorb	Farmers add nitrate in soil as fertilizer
Nonrenewable Resources	Resources that run out	Coal is a nonrenewable resource
Navigation	Finding directions	Navigation in geography uses maps
North Star	Bright star in the north	The north star guides travelers
Night Sky	Sky seen at night	Night sky science shows constellations

Medicine & Health (N Words in Medicine)

Word	Meaning	Example
Nerve Cell	Cell that sends signals	A nerve cell definition is another name for neuron
Nephron	Kidney filter	The nephron in kidney removes waste
Nasal Cavity	Air passage in nose	The nasal cavity function filters air
Nutrition	Study of nutrients	Nutrition science explains food health
Nausea	Feeling of sickness	Nausea medical term means stomach upset
Neonatal	Relating to newborns	Neonatal medicine treats infants
Neurology	Study of the nervous system	Neurology science treats brain disorders
Narcolepsy	Sleep disorder	Narcolepsy causes sudden sleep attacks
Necrosis	Death of body tissue	Doctors treat necrosis quickly
Neurotransmitter	Chemical in the brain	Dopamine is a neurotransmitter

Math & Technology (N Words in Math)

Word	Meaning	Example
Numerator	Top number in a fraction	The numerator in fractions shows part of a whole
Number Line	A line showing numbers	A number line helps in math
Natural Numbers	Counting numbers	Natural numbers are 1, 2, 3…
Null Set	Set with no elements	A null set math is empty
Negative Numbers	Numbers less than zero	Negative numbers are below zero
Numerical Value	Value of a number	Each digit has a numerical value
Notation	Symbols in math	Algebra uses notation in math
Nonlinear Equation	Equation with curves	A parabola is a nonlinear equation
Network	Connected system	A computer network shares data
Nanosecond	One billionth of a second	A nanosecond is very fast

General Science (Easy Vocabulary with N)

Word	Meaning	Example
Nature	Living world	Nature in science includes plants and animals
Neutral	Without charge	Neutral meaning in science is no charge
Normal	Standard condition	Normal in science means usual state
Newtons	Force units	Push measured in newtons
Nano Particles	Tiny materials	Nano particles act differently
Navigation	Finding way	Navigation science uses stars
North Wind	Wind from north	The north wind is cold
Natural Law	Universal rule	Gravity is a natural law
Newtonmeter	Tool for measuring force	A Newtonmeter checks strength
Normal Pressure	Standard air pressure	Sea level has normal pressure

Environmental Science (N Words in Environment)

Word	Meaning	Example
Nitrogen Fixation	Process of converting nitrogen gas into usable form	Bacteria help in nitrogen fixation for plants
Nitrogen Dioxide	Harmful gas and air pollutant	Cars release nitrogen dioxide into the air
Nitrate Pollution	Water pollution by nitrate compounds	Fertilizers cause nitrate pollution in rivers
Natural Habitat	Place where species live	Tigers survive in their natural habitat
Noise Pollution	Harmful sound affecting environment	Cities face noise pollution daily
Nonpoint Source	Pollution from many sources	Farms cause nonpoint source pollution
Nutrient Cycle	Movement of nutrients in ecosystems	Forests maintain a nutrient cycle
Nutrient Deficiency	Lack of key nutrients	Crops fail with nutrient deficiency
Native Species	Species living naturally in a region	Pandas are native species of China
Non-biodegradable	Cannot be broken by nature	Plastic is non-biodegradable waste

Astronomy (N Words in Space Science)

Word	Meaning	Example
Near-Earth Object	Asteroid close to Earth	NASA tracks each near-Earth object
Neutron Star	Dense star made of neutrons	A neutron star forms after a supernova
Nova	Sudden brightening of a star	A nova happens when a star flares
NASA	Space research agency	NASA sends astronauts to space
Northern Lights	Natural light display in sky	The northern lights glow in winter
Nadir	Lowest point in sky	The nadir is opposite to zenith
Navigation Satellite	Satellite for maps and GPS	A navigation satellite helps track locations
Naked Eye	Seeing without tools	The moon is visible with the naked eye
Near Infrared	Wavelength just beyond visible light	Near infrared telescopes study space
Night Vision	Ability to see in dark	Soldiers use night vision goggles

Ecology (N Words in Ecology)

Word	Meaning	Example
Nutrient	Essential chemical for growth	Plants need nutrients for life
Nitrogen Fixer	Organism that fixes nitrogen	Legumes are nitrogen fixers
Natural Balance	Stability in ecosystems	Forests show natural balance
Niche Adaptation	How species adapt roles	Birds show niche adaptation
Nectar	Sweet liquid in flowers	Bees collect nectar
Nutrient Flow	Energy transfer in ecosystems	Nutrient flow links plants and animals
Non-native Species	Species introduced elsewhere	Rabbits in Australia are non-native species
Nutrient Cycling	Process of recycling nutrients	Soil supports nutrient cycling
Net Primary Production	Energy made by plants	Forests have high net primary production
Nitrogenous Waste	Waste with nitrogen	Fish release nitrogenous waste

Technology (N Words in Technology & Engineering)

Word	Meaning	Example
Nanorobots	Tiny machines built with nanotech	Nanorobots may cure diseases
Neural Network	Computer system like a brain	AI uses a neural network
Navigation System	Tool for directions	Cars have a navigation system
Network Node	Connection point in a network	WiFi uses network nodes
Numeric Code	Number-based code	Computers read numeric code
NAND Gate	Logic gate in electronics	NAND gates are in circuits
Non-volatile Memory	Memory that keeps data	SSDs use non-volatile memory
Nanofiber	Very thin fiber material	Clothes use nanofibers
Noise Reduction	Process to reduce sound	Phones have noise reduction
Network Security	Protection of data online	Network security stops hacking

Geology (N Words in Earth Rocks & Minerals)

Word	Meaning	Example
Nickel	Metal element in Earth	Nickel is used in coins
Nodule	Small rounded mineral	Manganese nodules are in oceans
Natural Disaster	Catastrophe from nature	Earthquakes are natural disasters
Non-clastic Rock	Rock not made of fragments	Limestone is non-clastic
Normal Fault	Crack in rocks	A normal fault shifts ground
Native Element	Pure form of an element	Gold is a native element
Nautilus Fossil	Ancient sea fossil	A nautilus fossil is spiral shaped
Nonrenewable Fuel	Fuel that runs out	Oil is nonrenewable fuel
Near Shore Zone	Coastal water area	Fish live in the near shore zone
Nappe	Large folded rock sheet	Alps show nappes in geology

Environmental Health & Human Impact

Word	Meaning	Example
Nutrient Pollution	Extra nutrients in water	Fertilizer causes nutrient pollution
Nuclear Waste	Radioactive waste	Nuclear waste needs safe storage
Noise Hazard	Harm from loud sound	Factories cause noise hazard
Nutritional Value	Health value of food	Fruits have high nutritional value
Nitrates in Water	Nitrogen compounds in water	Farms raise nitrates in water
Natural Disaster Risk	Chance of disasters	Islands face high natural disaster risk
Nanoplastics	Tiny plastic particles	Oceans are full of nanoplastics
Nutrient Runoff	Fertilizer entering rivers	Rain causes nutrient runoff
Nutrient Management	Balancing soil nutrients	Farmers practice nutrient management
Non-toxic	Safe, not poisonous	Vinegar is non-toxic

Conclusion

Science becomes easier when you build strong vocabulary. This guide on science words that start with N has shown how these terms appear in every subject, from nucleotides in biology to Newton’s law of motion in physics. You learned their meanings, saw examples, and explored how students meet them at different grade levels.

The power of words like nucleus, neuron, nitrogen, nebula, and nutrition lies in how they connect to big ideas in science. With this list of science words beginning with N, you can boost your learning, prepare for exams, and make complex ideas easier to understand. As scientists often say, “Knowledge grows word by word.”