130 Science Words That Start with B (With Meanings & Examples)

Understanding science starts with words. And the science words that start with B are full of meaning, discovery, and knowledge. From biology terms starting with B like bacteria to chemistry vocabulary B like bond, this guide gives you clear science word meanings B, simple explanations, and real-life examples.

This complete science glossary for learners is perfect for students, teachers, and curious minds. It’s written in easy English and filled with useful science vocabulary education tools like a word table, sample sentences, and more.

Biology Terms Starting with B

These biology terms starting with B relate to life, the body, and the environment.

Word	Meaning	Example
Bacteria	Tiny living organisms, some helpful, some harmful	Bacteria help us digest food.
Biome	A large area with plants and animals	The rainforest is a tropical biome.
Brain	Control center of the body	The brain sends signals to the body.
Blood	Fluid that carries oxygen in animals	Blood moves through veins and arteries.
Breathing	Taking in oxygen and letting out carbon dioxide	Breathing keeps us alive.
Backbone	Spine or vertebral column in animals	Humans have a strong backbone.
Bile	A fluid made by the liver to digest fat	Bile helps break down fatty foods.
Bladder	Organ that holds urine	The bladder stores pee until you release it.
Bronchi	Air passages that lead into the lungs	Air flows through the bronchi to the lungs.
Biosphere	All living parts of Earth	Plants and animals live in the biosphere.

Chemistry Vocabulary B

This chemistry vocabulary B group includes tools, substances, and reactions Science Words That Start with B.

Word	Meaning	Example
Beaker	A glass container for mixing substances	Pour the solution into a beaker.
Base	A substance with a pH above 7	Soap is made from a type of base.
Bond	The link between atoms	Water has strong hydrogen bonds.
Boiling Point	Temperature where a liquid becomes gas	Water boils at 100°C.
Bromine	A red-brown liquid element	Bromine is used in fire retardants.
Buffer	A substance that keeps pH steady	Buffers stop big pH changes in cells.
Bunsen Burner	A small gas burner used in labs	Light the Bunsen burner for the experiment.
Benzene	A chemical used in plastics	Benzene is toxic if inhaled.
Burette	A tube for delivering measured liquids	Use the burette to add acid slowly.
Bleach	A chemical used to whiten or disinfect	Bleach kills bacteria on surfaces.

Physics Terms B

These physics terms B relate to motion, energy, and measurement.

Word	Meaning	Example
Buoyancy	Ability to float in fluid	Boats float due to buoyancy.
Balance	A tool to measure weight	Use a balance to find the object’s mass.
Battery	A device that stores energy	The flashlight needs a battery.
Barometer	A tool for measuring air pressure	The barometer dropped before the storm.
Beta Particle	A type of radioactive particle	Beta particles are emitted from atoms.
Brightness	How much light is given off	The bulb’s brightness increases with power.
Bending	Changing shape by force	Bending a metal rod requires strong force.
Beam	A line of light or energy	The laser beam cut through the metal.
Bohr Model	A model of atomic structure	The Bohr model shows electrons in orbits.
Bounce	To move back after hitting a surface	Balls bounce due to elastic energy.

Earth & Space Science B Words

These terms relate to Earth, space, and the environment Science Words That Start with B.

Word	Meaning	Example
Basin	A low area where water collects	A river flows through the basin.
Bedrock	Solid rock under soil	Foundations rest on bedrock.
Blizzard	A strong snowstorm with wind	The blizzard closed all the roads.
Bog	Wetland with moss and still water	The frog lives in the bog.
Bar	A ridge of sand or rock in water	The ship hit a sand bar.
Bay	Water partly surrounded by land	The boat sailed into the bay.
Biosphere	Earth’s zone of life	All living things belong to the biosphere.
Biodegradable	Can be broken down naturally	Paper is biodegradable.
Beach	Land beside an ocean or lake	The beach is made of sand and rocks.
Boulder	A large rock	A boulder blocked the road.

General Science Vocabulary B

This part of the science glossary for learners includes general academic terms useful in all science fields.

Word	Meaning	Example
Balance	Even weight or forces	A balance keeps the scale level.
Bar graph	A chart that shows numbers using bars	The bar graph shows plant growth.
Binoculars	Tool for seeing far objects	Use binoculars to watch birds.
Binary	A system with two parts	Computers use binary code.
Behavior	How something acts or works	Animal behavior is studied in science.
Bias	A leaning towards one idea unfairly	Remove bias for fair testing.
Boundary	A dividing line or edge	The cell membrane is a boundary.
Body	The physical structure of a living thing	Exercise keeps the body healthy.
Burn	To destroy by heat or fire	Fire can burn trees in a forest.
Blueprint	A detailed plan or drawing	A DNA strand is like a blueprint for life.

Technology and Engineering Terms

Explore how science vocabulary education applies in technology and design Science Words That Start with B.

Word	Meaning	Example
Bolt	A metal fastener	Use a bolt to hold the machine part.
Battery	Stores electrical energy	The robot runs on a battery.
Blueprint	A design plan	Engineers follow a blueprint.
Bridge	A structure over a gap	Build a bridge using strong materials.
Breaker	A device that stops electricity flow	Flip the breaker to cut power.
Bit	A small unit of digital data	The file is 4 million bits large.
Button	A switch to control a machine	Press the button to start.
Bypass	A route around something	The bypass allows flow when one path is blocked.
Bearing	A device to reduce friction	Bearings help the wheel spin.
Belt	A loop that moves or connects parts	The belt runs the engine fan.

Environmental Science and Ecology Words

Words in this section help us understand our environment and how living things interact with it.

Word	Meaning	Example
Biodiversity	Variety of life in an area	Forests have rich biodiversity.
Biofuel	Fuel made from plants or animals	Biofuel is better for the planet.
Biodegrade	Break down naturally over time	Leaves biodegrade in the soil.
Biomass	Material from plants or animals used for energy	Biomass can power homes.
Biosystem	A group of living things working together	A coral reef is a biosystem.
Biocontrol	Using one species to control another	Ladybugs are used for biocontrol.
Biohazard	Dangerous to life	Biohazard signs warn of infection risk.
Balance	Stability in nature	Ecosystems need balance to survive.
Buffer zone	Area that protects one environment from another	The forest acts as a buffer zone.
Breeding	Producing offspring	Scientists study animal breeding.

Scientific Measurement & Tools Terms

Word	Meaning	Example
Barometer	Measures air pressure	The barometer shows a pressure drop.
Balance Scale	Tool to weigh objects	Use the balance scale to measure mass.
Buret	A tube for precise liquid measurement	Fill the buret before starting the test.
Boiling Tube	A glass tube for heating substances	Place the liquid in the boiling tube.
Biometric	Measures body characteristics	Biometric scans are used in labs.
Bioluminescence	Light made by living things	Jellyfish glow by bioluminescence.
Beam Balance	A type of scale with two pans	Compare weights with a beam balance.
Biosensor	Detects biological changes	The biosensor tracks blood sugar.
Burner	Heats substances in lab	Use the burner to boil water.
Bar	Unit of pressure measurement	The diver felt the pressure of two bars.

Medical & Human Biology Science Words

Word	Meaning	Example
Bone	Hard part of the body structure	The human body has 206 bones.
Brainstem	Base of the brain that controls basic functions	Breathing is controlled by the brainstem.
Biopsy	Removal of tissue for testing	The doctor took a biopsy to check the lump.
Blood Vessel	Tube that carries blood	Blood vessels transport oxygen.
Bronchus	Major air passage in lungs	Smoking can damage the bronchus.
Blister	A bubble on the skin filled with fluid	Heat can cause a blister.
Bandage	Used to cover a wound	Apply a bandage after cleaning the cut.
Bacteria	Can cause infections in the body	Bacteria can enter through a wound.
Basal Cell	Skin cell, sometimes cancerous	Basal cell cancer is common but treatable.
Birth	Process of a baby coming into the world	The nurse assisted during the birth.

Genetics and Cell Biology Terms

Word	Meaning	Example
Base Pair	Units that form DNA	DNA is made of base pairs.
Binary Fission	Cell division in bacteria	Bacteria multiply through binary fission.
Binding Site	Spot where molecules attach	Proteins have binding sites for enzymes.
Biogenesis	Life comes from other life	Biogenesis explains reproduction.
Bioinformatics	Use of computers in biology	Bioinformatics helps decode DNA.
Blastocyst	Early stage of embryo	The blastocyst implants in the uterus.
Budding	Asexual reproduction method	Yeast grows by budding.
Biopsy	Cell or tissue sample	A biopsy helps diagnose illness.
Basophil	A type of white blood cell	Basophils respond during allergic reactions.
B Cell	A type of immune system cell	B cells help produce antibodies.

Astronomy & Space Science B Words

Word	Meaning	Example
Binary Star	Two stars orbiting each other	A binary star system looks like one light.
Black Hole	A region in space with strong gravity	Nothing escapes a black hole.
Big Bang	The start of the universe	The Big Bang happened about 13.8 billion years ago.
Blue Giant	A large, hot star	A blue giant burns bright and fast.
Bolide	A very bright meteor	The bolide lit up the night sky.
Bright Star	A star that shines strongly	Sirius is a bright star in the sky.
Blue Shift	Light moves toward the blue spectrum	Blue shift means an object is getting closer.
Barred Spiral	Type of galaxy with a bar shape	Our Milky Way is a barred spiral galaxy.
Binary Planet	Two planets orbiting a center	Pluto and Charon may be a binary planet.
Basalt	Rock from cooled lava	The moon’s surface has basalt rock.

Behavioral & Psychology Science Words

Word	Meaning	Example
Behavior	How something acts	Scientists studied the dog’s behavior.
Brainwave	Electrical activity in the brain	Alpha brainwaves occur when you’re calm.
Bias	Preference that affects judgment	Bias can affect scientific results.
Belief	Acceptance of an idea	Belief systems influence behavior.
Boredom	Feeling of not being interested	Too much routine causes boredom.
Bonding	Forming close relationships	Bonding is important for child development.
Boundary	Emotional or physical limit	Healthy boundaries protect mental well-being.
Body Language	Non-verbal communication	Crossed arms can be negative body language.
Burnout	Emotional and physical tiredness	Stress leads to burnout in students.
Biofeedback	Using body data to control reactions	Biofeedback helps people relax.

Ecology and Agriculture B Words

Word	Meaning	Example
Biodiversity	Variety of life in nature	High biodiversity makes forests strong.
Bioswale	Landscape to collect water	A bioswale reduces stormwater runoff.
Bioaccumulation	Build-up of substances in organisms	Mercury shows bioaccumulation in fish.
Biomagnification	Toxins increasing up the food chain	Predators suffer from biomagnification.
Biotic	Related to living things	Biotic factors include plants and animals.
Bioreactor	Device to support biological reactions	Bioreactors help grow cells.
Biosecurity	Protecting from harmful organisms	Farms need strong biosecurity systems.
Bioclimatic	Related to climate and living things	Bioclimatic zones affect crops.
Biopesticide	Natural pest control	Neem oil is a biopesticide.
Breeding	Controlled reproduction	Farmers use selective breeding.

Conclusion

The 130 science words that start with B are more than just letters. They are your tools to understand life, earth, energy, and everything in between. These words appear in biology, chemistry, physics, and environmental science. They’re also part of everyday conversations, classrooms, and experiments.

Keep exploring new words. Practice them. Use flashcards, posters, and science classroom posters to help your memory. And don’t forget—every big science idea starts with understanding the right word.