If you don’t find a definition for a term you found on Reeko’s site, feel free to email Reeko your word suggestion and he’ll update this page accordingly.
And don’t forget – glossary terms are scattered throughout the site – in the games, science experiments, news articles, and under various laboratory rugs. If you are looking for a longer, more elaborate definition of a science word, you can take a quick peek at the Reeko’s online dictionary of science words here.
abiotic factor – a nonliving part of a ecosystem.
absolute zero – the lowest temperature that can possibly be reached in our Universe. Scientists have gotten very close to reaching absolute zero but it is impossible to reach it.
acid – a sour tasting, corrosive substance – the opposite of a base substance. Acidic solutions will turn a litmus red.
air pressure – the force put on a given area by the weight of the air around it.
alkali – a substance having marked basic properties (i.e. substance with properties of a base).
aluminum (Al) – element #13 on the periodic table, is a silvery-white metal. It is non-magnetic and an excellent electrical conductor. It is of low density and high ductility. Aluminum’s appearance is dulled and its reactivity is passivated by a film of aluminum oxide that naturally forms on the surface of the metal under normal conditions. The oxide film results in a material that resists corrosion. The film can be thickened using electrolysis. It shows some hints of nonmetal behavior as well as the more typical metal reaction. Pure aluminum is quite soft and lacking in strength. Aluminum used in commercial applications has small amounts of silicon and iron added, resulting in greatly improved strength and hardness.
argon (Ar) – element #18 on the periodic table, is a noble gas. It is colorless, odorless and extremely unreactive. Argon forms no stable compounds at room temperature.
atmosphere – the blanket of gases that surrounds the Earth. Used in a sentence: burr, it’s cold in here, it must be something in the atmosphere.
atoms – made up of protons and neutrons in a central nucleus surrounded by electrons. The smallest particle of a chemical element that can take part in a chemical reaction without being permanently changed.
anemometer – a device used to measure the speed of wind.
angiosperm – a seed plant that produces flowers.
antimatter – the opposite of regular matter. For every particle of ordinary matter there is an almost identical antiparticle of antimatter.
aquifer – an underground layer of loose rock, sand, or gravel that holds water in its spaces.
asexual reproduction – the production of a new organism from only one cell.
asteroid belt – region between Mars and Jupiter where most asteroids are found.
atmosphere – the blanket of air that surrounds the Earth. It is thickest near the ground and gradually fades away to nothing in outerspace.
bacteria – members of either of two kingdoms of one-celled living things that have no nucleus, or center, in their cell body.
barometer – a device used to measure the pressure of the atmosphere. The barometer unit of measure is called millibars.
base – a bitter tasting substance (and often slimy) – the opposite of a acid substance. Base solutions will turn a litmus blue.
battery – a device that produces electricity by means of chemical reaction. A battery consist of one or more units called electric cells. Each cell has all the chemicals and parts needed to produce an electric current.
bernoulli effect – described by Swiss mathematician Daniel Bernoulli in 1738. Bernoulli’s theorem (sometimes called the Venturi effect) implies that a decrease in fluid pressure is associated with an increase in the fluid’s velocity (speed). It’s the basics for aircraft wing design explaining that air flowing over the upper, curved part of the wing moves faster than the air on the underside of the wing so that the pressure underneath is greater and hence causes lift.
beryllium (Be) – element #4 on the periodic table, has the highest melting point of the light metals, melting at 1278C. On the surface of beryllium a thin layer of the hard oxide BeO forms, protecting the metal from further attack by water or air. As a result of the BeO layer, beryllium does not oxidize in air even at 600C and it resists corrosion by concentrated nitric acid. Beryllium also has high thermal conductivity and is nonmagnetic.
Big Bang – take a large hardcover book and hold it flat about the level of your eyes. On a hard, flat surface, drop the book. That’s a big bang.
biome – one of Earth’s large ecosystems, with its own kind of climate, soil, plants, and animals.
biosphere – part of the earth system located between the geospehere and the atmosphere, in which life can exists.
biotic factor – a living part of a ecosystem.
boron (B) – element #5 on the periodic table, is a metalloid, intermediate between metals and non-metals. It exists in many polymorphs (different crystal lattice structures), some more metallic than others. Metallic boron is extremely hard and has a very high melting point. Boron does not generally make ionic bonds, it forms stable covalent bonds. Boron can transmit portions of infrared light. Boron is a poor room temperature conductor of electricity but its conductivity improves markedly at higher temperatures.
buoyancy – the ability to float, or in more technical terms – the upward forces exerted by a fluid on a body in it.
boiling point – the temperature at which the vapor pressure of a liquid is one atmosphere.
calcium (Ca) – element #20 on the periodic table, is reactive and, for a metal, soft. In contact with air, calcium develops a mixed oxide and nitride coating, which protects it from further corrosion. Calcium reacts easily with water and acids and the metal burns brightly in air, forming mainly the nitride.
cambium – the layer in plants that separates the xylem from the phloem.
capacitor – a device that stores electric energy in the form of an electric charge.
carbon (C) – element #6 on the periodic table, is one of the softest substances and has the highest melting/sublimation point of all the elements and, in the form of diamond, has the highest thermal conductivity of any element. Carbon exists in several allotropes, including graphite, diamond, amorphous carbon, fullerines and nanotubes
carbon cycle – the continuous exchange of carbon dioxide and oxygen moving among living things.
carbon dioxide – a heavy colorless gas that does not support combustion, dissolves in water to form carbonic acid, is formed in animal respiration and in the decay or combustion of animal and vegetable matter, and is absorbed from the air by plants in photosynthesis.
carnivore – an animal that eats another animal.
catalyst – something that triggers or increases the rate of a chemical reaction
Celsius – a unit of measurement for temperature. Water freezes at 0ºC (zero degrees Celsius) and boils at 100°C (100 degrees Celsius).
capillary action – the tendency of liquids to move into or out of tiny, hair like passages.
cell – the smallest unit of living matter.
charge – the state of an atom that has lost or gained an electron.
chlorophyll – a green chemical in plant cells that allows plants to use the Sun’s energy for making food.
chlorine (Cl) – element #17 on the periodic table, is a greenish-yellow, diatomic, dense gas with a sharp smell. It is not found free in nature as it combines readily with nearly all other elements. In its liquid and solid form it is a powerful bleaching, oxidizing and disinfecting agent.
chemical reaction – a process by which one substance is chemically converted to another. Chemical reactions involve the formation or destruction of bonds between atoms.
circuit – the path followed by an electric current. Electricity must flow in a circuit to do useful work.
cirrus cloud – a high-altitude cloud with a featherlike shape, made of ice crystals.
coanda effect – described by Henri Coanda, a Romanian scientist, in the 1930’s. This effect describes the tendency of moving air of fluids to follow the nearby curved or inclined surface.
commensalism – a relationship between two kids of organisms that benefits one without harming the other.
coriolis effect – the curving of the path of a moving object caused by the Earth’s rotation.
comet – a ‘dirty snowball” orbiting the Sun. It is a mixture of ices, frozen gases, rock, and dust left over from the formation of our solar system.
condensation – when a substance changes state from a gas to a liquid.
conductor – a thing that transmits heat, electricity, light, sound or other form of energy.
constellation – patterns formed by groups of stars in the sky.
control – in a science experiment, it is important to keep at least one variable constant so that the impact of the other variables can be accurately measured.
correlation – the relationship between two variables such that the value of one variable can be used to generate an expectation about another variable.
cotyledon – a tiny leaflike structure, also called a seedleaf, inside the seed of an angiosperm.
cumulus cloud – a puffy cloud that appears to rise up from a flat bottom.
current – the movement or flow of electric charges
dark matter – matter that cannot be detected by our modern day instruments but can be guessed that it does exist because of gravitational interactions that it exhibits.
doesn’t matter – well, yes, actually it does matter…
dicot – an angiosperm with two cotyledons in each seed.
decibel – a unit of measurement for sound, it measures the loudness or volume of the sound waves.
deciduous forest – a forest biome with many kinds of trees that lose their leaves each autumn.
density – the ratio of the mass of a body to its volume, usually expressed as its specific gravity.
dynamo – a device that creates electricity by turning around a magnet near a coil of wire.
ecology – the study of how living and non-living things interact with each other.
ecosystem – a isolated group of living (plants, animals, people) and non-living (rocks) things that coexist together and interact which each other to ensure each others’ survival.
electric current – see current.
electrolysis – splitting a substance into the separate chemicals that make it up, by passing an electric current through it.
electrons – a negatively charged subatomic particle. Electrons are found at varying distances from a atom’s nucleus. They make up almost the entire volume of a atom but only account for a small part of the atom’s mass. Compare to protons.
element – a basic chemical substance in which all the atoms are the same, and different from the atoms of any other substance.
embryo – the immature plant inside a seed.
emulsion – tiny droplets of one liquid floating in another liquid, such as oil droplets floating in water.
energy – the name given to the ability to do work.
epidermis – an outermost layer of such plant parts as roots and leaves. Also refers to human skin. Used in a sentence: OMG, your epidermis is showing!
evaporation – the slow changing of a liquid to a gas.
exothermic – in chemistry, exothermic refers to a reaction that releases energy, generally in the form of heat.
fact – something that is known to be true. For instance, it is a fact the Reeko is a scientific genius.
fluorine (F) – element #9 on the periodic table, is the most reactive and the most electronegative of all the elements. Fluorine is a pale yellow, diatomic, highly corrosive, flammable gas, with a pungent odor. It is the lightest halogen. It reacts violently with water to produce oxygen and the extremely corrosive hydrofluoric acid.
food chain – a chain of organisms of which each members uses the lower member as a source of food (people eat cows which eat plants). Applebees is at the top of the food chain and McDonalds is at the bottom.
food web – the overlapping food chains in an ecosystem.
freezing point – the temperature at which a liquid becomes a solid. Increased pressure usually raises the freezing point.
frond- the leaf of a fern. Used in a sentence: I like Bob – he’s my best frond in the whole wide world.
friction – the resistance that occurs when two objects rub together.
fungus – members of a kingdom that contain one-celled and many-celled living things that absorb food from their environment.
galaxy – a collection of billions of stars. Our Sun belongs to the Milky Way galaxy.
grasslands – a biome where grasses, not trees, are the main plant life. Prairies are one kind of grassland region.
gravity – the attractive central gravitational force exerted by a celestial body such as earth.
greenhouse effect – the warming of the atmosphere caused by the atmosphere allowing shortwave radiation, which heats the Earth, to pass through without a hall pass.
greenhouse gas – the gases in the atmosphere, including carbon dioxide, methane, nitrous oxide, and water vapor, that contribute to the greenhouse effect.
habitat – the place where a plant or animal normally lives and grows.
herbivore – an animal that eats plants, algae, or other producers.
helium (He) – element #2 on the periodic table, is a light, odorless, colorless, inert, monatomic gas. It can form diatomic molecules, but only weakly and at temperatures close to absolute zero. Helium has the lowest melting point of any element and its boiling point is close to absolute zero. Unlike any other element, helium does not solidify but remains a liquid down to absolute zero (0 K) under ordinary pressures.
humidity – the amount of water vapor in the air.
hydrogen (H) – element #1 on the periodic table, is the simplest element of all, and the lightest. It is also by far the most common element in the Universe. Over 90 percent of the atoms in the Universe are hydrogen. In its commonest form, the hydrogen atom is made of one proton, one electron, and no neutrons. Hydrogen is the only element that can exist without neutrons.
hypothesis – this is your proposed explanation of your experiment. It is usually formed based on previous experience or your preliminary observations.
immiscible – incapable of mixing or attaining homogeneity.
induction – the process by which an object having electrical or magnetic properties produces similar properties in a nearby object, usually without direct contact.
inertia – the tendency of a moving object to keep moving in a straight line or of any object to resist a change on motion.
inner planet – a planet between the Sun and the asteroid belt (Mercury, Venus, Earth, and Mars).
insolation – the amount of the Sun’s energy that reaches Earth at a given time and place.
invertebrate – an animal that does not have a backbone or another name for the schoolyard bully.
inertia – the tendency of a body to remain at rest or stay in motion unless acted upon by an external force.
isobar – a line on a weather map connecting places with equal air pressure.
ions – Atoms that carry an electric charge, either positive or negative. If an atom gains an electron it takes on a negative charge. If the atom loses an electron it takes on a positive charge.
lightening – to make something lighter, clearer, or less dim.
lightning – a powerful flash of electricity between the negative electrical charges in clouds or between a cloud and the ground.
limiting factor – anything that controls the growth or survival of a population.
liquid nitrogen – the liquid state of the element nitrogen. It’s used in science experiments to cool materials. It is interesting to work with because it boils at -320 degrees.
lithium (Li) – element #3 on the periodic table, is soft and silvery white and it is the least dense of the metals. It is highly reactive and does not occur freely in nature. Freshly cut surfaces oxidize rapidly in air to form a black oxide coating. It is the only common metal that reacts with nitrogen at room temperature, forming lithium nitride. Lithium burns with a crimson flame, but when the metal burns sufficiently well, the flame becomes a brilliant white. Lithium has a high specific heat capacity and it exists as a liquid over a wide temperature range.
magnesium – element #12 on the periodic table, is a silvery-white, low density, reasonably strong metal that tarnishes in air to form a thin oxide coating. Magnesium and its alloys have very good corrosion resistance and good high temperature mechanical properties. The metal reacts with water to produce hydrogen gas. When it burns in air, magnesium produces a brilliant white light.
magnetism (Mg) – the force that electric currents exert on other electric currents.
mass – often defined as the amount of matter in an object. Note that mass and weight are not the same thing. Weight is the force on an object due to the gravitational pull of a planet or other heavenly body. Mass on the other hand, remains constant, no matter where it is.
melting point – the temperature at which the vapor pressure of the solid and the liquid are the same and the pressure totals one atmosphere.
meteor – a chunk of rock from space that burns up as it travels through the Earth’s atmosphere.
meteorite – a chunk of rock from space that strikes the surface of the Earth of the Moon.
mole – the mass of a substance, in grams, that is equal to the substances molecular weight. The number of particles in one mole of a substance is called Avogadro’s number.
molecule – one of the basic units of matter. It is the smallest particle into which a substance can be divided and still have he chemical identity of the original substance.
momentum – the speed or force of something that is moving.
monocot – an angiosperm with one cotyledon in each seed.
mutualism – a relationship between two kinds of organisms that benefits both.
neon (Ne) – element #10 on the periodic table, is a light, very inert gas. Colorless under normal conditions, its glows a reddish-orange in a vacuum discharge tube. Neon forms no known stable compounds.
nitrogen (N) – element #7 on the periodic table, a colorless, odorless, tasteless, diatomic and generally inert gas at standard temperature and pressure. At atmospheric pressure, nitrogen is liquid between 63 K and 77 K. Liquids colder than this are considerably more expensive to make than liquid nitrogen is.
nitrogen cycle – the continuous trapping of nitrogen gas into compounds in the soil and its return to the air.
omnivore – an animal that eats both plants and animals.
osmosis – the natural passage or diffusion of water (or other liquids) through a semi permeable membrane.
outer planet – one of the five planets beyond the asteroid belt (Jupiter, Saturn, Uranus, Neptune, Pluto)
oxidize – to combine with oxygen.
oxygen (O) – element #8 on the periodic table, a colorless, odorless, tasteless gas that is the most plentiful element in the Earth’s crust. It was discovered in 1772 by Swedish chemist Carl Wilhelm Scheele.
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parasitism – a relationship in which one organism lives in or on another organism and benefits from that relationship while the other organism may be harmed by it.
phloem – the tissue through which food from the leaves moves down through the rest of a plant.
phosphorus (P) – element #15 on the periodic table, is a highly reactive, waxy, white-yellow, transparent solid with acrid fumes. It emits a weak green glow (luminescence) in the presence of oxygen. It is insoluble in water. White phosphorus ignites spontaneously in air. Phosphorus exists in two other main allotropic forms: red, and black (or violet). Red phosphorus results when white phosphorus is heated or exposed to sunlight. Black phosphorus is the least reactive allotrope and has a graphite-like structure.
photosynthesis – the food-making process in green plants that uses sunlight.
planet – any of the nine major objects that travel around the Sun.
pollination – the transfer of a pollen grain to the egg-producing part of a plant.
potassium (K) – element #19 on the periodic table, is silvery-white, low melting, metal soft enough to be easily cut with a knife. It tarnishes rapidly in air, forming a dull oxide coating. Potassium burns with a lilac colored flame. It is extremely reactive, reacting violently with water.
potential – the amount of electrification of a point with reference to some standard.
pot of gold – a hidden treasure, many of which can be found in Reeko’s Mad Scientist Lab.
precipitation – any form of water particles that falls from the atmosphere and reaches the ground – rain, snow, sleet, etc.
predator – an animal that hunts other animals for food.
pressure – the application of a steady force upon another object.
protist – a member of a kingdom that contains one-celled and many-celled living things, some that make food and some that hunt for food. May also refer to the act of civil disobedience where you march around with signs protisting something that makes you mad.
protons – a positively charged subatomic particle. Protons, along with other subatomic particles called Neutrons, make up the nucleus of a atom. The number of protons in an atom is called the atomic number of the element. Compare to electrons.
quark – believed to be on of the basic building blocks of matter. It is also the sound that British ducks make.
reaction – when two or more chemicals combine to make a new chemical substance.
refraction – the bending of a wave path, as of light or sound, at the boundary between two different mediums.
relative humidity – a comparison between how much water vapor is in the air and how much the air could hold at a given temperature if it were full, or saturated.
resistance – how much an object resists or opposes any electrical current that attempts to pass through it.
resonance – when the vibrations of a substance, such as the wood of a violin, correspond to the air vibrations which make the sound.
rhizoid – one of the hairlike fibers that anchor a moss to the soil and take in water from the soil.
rhizome – the underground stem of a fern.
scandium (Sc) – element #21 on the periodic table, is a soft, light, silvery-white metal, which becomes slightly tinged with yellow or pink when exposure to air. Scandium is almost as light as aluminum but it has a much higher melting point. It is therefore of potential specialty use in aircraft – scandium will not be used generally because it is much more expensive than aluminum. Scandium reacts with many acids.
secondary battery – a battery that can be recharged.
sexual reproduction – the production of a new organism from a female sex cell and a male sex cell.
silicon (Si) – element #14 on the periodic table, is a hard, relatively inert metalloid and in crystalline form is very brittle with a marked metallic luster. Silicon occurs mainly in nature as the oxide and as silicates. The solid form of silicon does not react with oxygen, water and most acids. Silicon reacts with halogens or dilute alkalis. Silicon also has the unusual property that it expands as it freezes (like water).
sodium (Na) – element #11 on the periodic table, is a soft, silvery-white metal. Freshly cut surfaces oxidize rapidly in air to form a dull, oxide coating. Sodium burns in air with a brilliant yellow flame. Sodium floats on water, because its density is lower than water’s. It also reacts vigorously with water to produce sodium hydroxide and hydrogen gas. Explosions occur when the heat generated by the sodium-water reaction ignites the resulting hydrogen gas.
specific gravity – the ratio of the density of a body to the density of water, the latter being taken as unity.
static electricity – describes the situation where objects carry a charge.
stratus cloud – a cloud that forms in a blanket like layer.
sulfur (S) – element # 16 on the periodic table, is a soft, pale yellow, odorless, brittle solid. It is insoluble in water. It burns with a blue flame, oxidizing to sulfur dioxide. Sulfur exists in several crystalline and amorphous allotropes. The best known sulfur compound is hydrogen sulfide. This is a toxic gas that smells like rotten eggs; the smell is used in stink bombs, many of which release a small amount of hydrogen sulfide.
symbiosis – a relationship between two kinds of organisms that lasts over time.
titanium (Ti) – element #22 on the periodic table, is a light, silvery-white, hard, lustrous metal. It has excellent strength and corrosion resistance and also has a high strength to weight ratio. At high temperatures the metal will burn in air. Titanium is ductile and it is malleable when heated. It is insoluble in water, but soluble in concentrated acids.
taiga – a cool forest biome of conifers in the upper Northern Hemisphere.
transformer – a device that changes the voltage of electricity.
treasure – something that is very valuable to you. Could be your pet dog, pirate’s loot, or a pot of gold.
tropism – a response of a plant toward or away from stimulus.
troposphere – the layer of the atmosphere closet to the Earth’s surface.
tundra – large, treeless plain in the arctic regions where the ground is frozen all year.
turbine – pronounced TUR bihn or pronounced TUR byn, is a device with a rotor turned by a moving fluid, such as water, steam, gas, or wind. A turbine changes kinetic energy (energy of movement) into mechanical energy (energy in the form of mechanical power).
uranus – we just had to put this word in the glossary because, well, it sounds funny…
vascular – containing plant tissue through which water moves up and food moves down.
voltage – differences in potential (or electric state) related to the electrical forces that ‘push’ charges through a conductor. Can be thought of as the pressure which pushes electricity through a wire.
weight – the force on an object due to the gravitational pull of a planet or other heavenly body.
wock – hard, inanimate object that you throw at a wabbit.
xylem – the tissue through which water and minerals move up through a plant.