Category: Science Dictionary

Chlorophyll: A green-coloured compound or ‘pigment’ in plants that converts radiant energy to chemical energy through the process of photosynthesis.

Chemical reaction: The formation of new substances from one or more reactants, by breaking existing electrical bonds and creating others.

Chemical indicator: Any substance used to classify another, often by changing colour.

Chemical element: Any of the more than 100 known substances that cannot be separated into simpler substances and that individually or in combination constitute all matter.

Cereal: A breakfast food prepared from grain

Centrifugal force: Centrifugal force is the effect that tends to move an object away from the centre of a circle it is rotating about (a consequence of inertia).

Centre of mass: The point at which the entire mass of a body can be considered to be concentrated. Centre of mass / gravity The point at which the entire mass of a body can be considered to be concentrated.

Cells: The basic structural and functional unit of all living organisms. Cells can exist as independent units of life (as in monads) or may form colonies or tissues as in higher plants, animals or human beings.

Celestial bodies: Objects that are naturally occurring physical entities or structures, that current science has demonstrated to exist in outer space.

Catalyst: A substance that initiates or accelerates a chemical reaction without itself being affected

Cartesian diver: The Cartesian diver was first explained by René Descartes, a sixteenth-century French mathematician

Carcinogenic: A carcinogenic substance is any substance that produces cancer or stimulates the production of cancerous cells.

Carbon dioxide: Carbon dioxide is a colourless, odourless incombustible gas present in the atmosphere. It is formed during the breathing of living organisms, the decomposition and combustion of organic compounds, and in the reaction of acids with carbonates: used in fizzy drinks, fire extinguishers, and as dry ice for refrigeration.

Caramel: Made by cooking sugar slowly, used in candy making and sweetening of foods

Capillary action: The flow of liquids through porous media, such as the flow of water through blotting paper.

Capacitor: A capacitor is an electrical component used to control the flow of charge in a circuit. The name derives from their capacity to store an electric charge. Capacitors consist of two conducting surfaces separated by an insulator; a wire lead is connected to each surface. A capacitor can store electric energy and discharge it at a determined rate.

Camera obscura: A darkened enclosure in which images of outside objects are projected through a small aperture or lens onto a facing surface. A camera obscura uses the same principles as a regular camera.

Calligraphy: It is often called the ‘art of fancy lettering’ by means of an ink pen. This style of writing is described as a script and is often used for wedding invitations etc.

Calcium carbonate: Calcium carbonate (CaCO3) is a common substance found in rock in all parts of the world, and is the main component of shells of marine organisms like snails, pearls, seashells and corals. Saltwater reef tank keepers have to dose or supplement this compound in order for corals to grow. Corals need calcium carbonate to grow

Calcium: A mineral salt that strengthens the bones.

Café Wall Illusion: This optical illusion was first observed and described by Doctor Richard Gregory when he noticed the curious effect in the tiles of the wall of a café in Bristol. This optical illusion makes the parallel straight horizontal lines appear to be bent. This illusion consists of alternating light and dark ‘bricks’ that are laid in staggered rows.

Buzzer: An electrical mechanism that produces an intermittent current and an audible buzzing sound, or series of sounds, when electrical current flows through it.

Buoyancy: The ability of water to support weight allowing an object to float.

Block and tackle: A block and tackle is a compound pulley where several pulleys are mounted on each axle, further increasing the mechanical advantage.

Biosphere: A ‘biosphere’, also called an ‘ecospheres’, is a mostly closed ecosystem of a specific size that contains a mix of plants and animals that is completely self-sufficient.

Binaural hearing: The perception of sound by stimulation of two ears affecting a listener’s ability to identify the location or origin of a detected sound in direction and distance.

Binary code: Electronic data used in computers. The circuit is either on or off and is represented with either a 1 or 0. The system uses the digits 0 and 1 to represent a letter, numeral or other character in a computer.

Big dipper: A group of seven bright stars in the northern sky, near the pole – also called the constellation Ursa Major or the Great Bear.

Biceps: The biceps of a human is a muscle located on the upper arm. The biceps has several functions, the most important being to rotate the forearm and to flex the elbow.

Bernoulli’s principle: The principle of conservation of energy applied to fluid flow: as the speed of a moving fluid increases, the air pressure within the fluid decreases. Named after Daniel Bernoulli, a Swiss mathematician and scientist, Bernoulli is famous for his work in the field of fluid dynamics. In 1738 he wrote a book called Hydrodynamica. In this book he explained his theories about how gases and fluids move, and how the speed at which they move affects the pressure they exert on objects they flow around.

Berlese funnel: A device in which soil is placed; heat and light are applied from above, forcing bugs into a container below it. Named after Antonio Berlese an Italian entomologist.

Benjamin Franklin: Benjamin Franklin, (January 17, 1706 – April 17, 1790) was one of the Founding Fathers of the United States of America. Franklin was a leading author and printer, satirist, political theorist, politician, scientist, inventor, civic activist, statesman, and diplomat. As a scientist, he was a major figure in the Enlightenment and the history of physics for his discoveries and theories regarding electricity.

Base: The opposite of an acid. A Base has a pH-level of more than 7.0 up to 14.0 (A pH of 7 is neutral)

Barycentre: The point at the centre of a system; an average point, weighted according to mass or other attribute.

Barometer: An instrument for measuring atmospheric pressure, used especially in weather forecasting, but is also used to measure altitude.

Balance point: The point along the length of the shaft at which it will balance itself when placed on a fulcrum.

Balance: A state of equilibrium

Bacteria: Very small living organisms made of only one cell which are present everywhere (the air, the soil, on the skin). Many types of bacteria can cause diseases, but others can be very helpful to humans.

Atoms: The smallest component of an element or ‘matter’ having the chemical properties of the element.

Atmosphere: The gases surrounding the Earth or any astronomical body of sufficient mass, held together by the gravity of the body.

Astrolabe: An ancient circular instrument used to observe and calculate the position of celestial bodies.

Anemometer: An anemometer is a meteorological instrument that measures wind speed, either be gauging velocity or pressure.

Amplify: To increase the volume of or ‘amplify’ sound.

Amplifies: To make larger or more powerful; increase.

Amplifier: An electronic device that changes, usually increases, the strength or amplitude of a signal passing through it

Ambient Temperature: The temperature of the surrounding air.

Ambergris: A sperm whale secretion. Sperm whales produce it to protect their stomachs from the beaks of the cuttlefish they swallow, and formerly valued greatly in the manufacturing process of perfumes.

Altitude: The height above sea level or above the earth’s surface.

Alkaline: Relating to or containing an alkali, hence having a pH greater than 7. Alkaline batteries have potassium hydroxide as its electrolyte and a zinc / manganese dioxide cell.

Air pressure (Atmospheric pressure): Air pressure is the weight of the atmosphere pressing down on the earth. It is measured by a barometer in units called millibars.

Air: A mixture of gases (especially oxygen) required for breathing; the stuff that the atmosphere consists of.

Acid rain: Rain which is unusually acidic (pH of less than the natural range of 5 to 6), caused mainly by atmospheric pollution with sulphur dioxide and nitrogen compounds.

Acid: Any water-soluble compound having a sour taste and capable of turning litmus red and reacting with a base to form a salt. Acid has a pH-level of less than 7.0 (A pH of 7 is neutral).