Page 48 - Curriculum Visions Dynamic Book

Glossary of technical terms
acid: compounds containing hydrogen that can attack and dissolve many substances.Acids are described as weak or strong, dilute or concentrated, mineral or organic.
acidity: a general term for the strength of an acid in a solution.
anion: a negatively charged atom or group of atoms.
anode: the negative terminal of a battery or the positive electrode of an electrolysis cell.
base: a compound that may be soapy to the touch and that can react with an acid in water to form a salt and water.
calcite: the crystalline form of calcium carbonate.
cathode: the positive terminal of a battery or the negative electrode of an electrolysis cell.
cation: a positively charged atom or group of atoms.
caustic: a substance that can cause burns if it touches the skin.
compound: a chemical consisting of two or more elements chemically bonded together. Calcium atoms can combine with carbon atoms and oxygen atoms to make calcium carbonate, a compound of all three atoms.
coral reef: a region of the seabed where corals grow in massive banks.
corrosion: the slow decay of a substance resulting from contact with gases and liquids in the environment.The term
is often applied to metals. Rust is the corrosion of iron.
decompose: to break down a substance (for example, by heat or with the aid of a catalyst) into simpler components. In such a chemical reaction only one substance
is involved.
dehydration: the removal of water from a substance by heating it, placing it in a dry atmosphere or using a drying agent.
dilute acid: an acid whose concentration has been reduced by a large proportion
of water.
dissolve: to break down a substance in a solution without reacting.
electrode: a conductor that forms one terminal of a cell.
facing: sheets of stone cut to form the decorative outer surface of a building. It is a form of cladding. On modern buildings it is also sometimes called siding.
kiln: a structure designed for baking minerals. Lime, brick and pottery kilns are all common.
hydration: the absorption of water by a substance. Hydrated materials are not “wet” but remain firm, apparently dry solids. In some cases hydration makes the substance change colour, in many other cases there
is no colour change, simply a change in volume.
insoluble: a substance that will not dissolve.
ion: an atom that has gained or lost an electron and so developed an electrical charge. Ions behave differently from electrically neutral atoms and molecules. They can move in an electric field and they can also bind strongly to solvent molecules such as water. Positively charged ions are called cations; negatively charged ions are called anions. Ions carry electrical current through solutions.
lava: a name for molten rock that pours from volcanoes.The word is also used for the solid rock that forms from the liquid.
mineral: a solid substance made of just one element or chemical compound. Calcite is a mineral because it consists only of calcium carbonate; halite is a mineral because it contains only sodium chloride; quartz is a mineral because it consists of only silicon dioxide.
mineral-laden: a solution close to saturation.
neutralization: the reaction of acids and bases to produce a salt and water.The reaction causes hydrogen from the acid and hydroxide from the base to be changed
to water. For example, hydrochloric acid reacts with sodium hydroxide to form common salt and water.The term is more generally used for any reaction in which the pH changes toward 7.0, which is the pH of a neutral solution.
ore: a rock containing enough of a useful substance to make mining it worthwhile.
oxidation: a reaction in which the oxidizing agent removes electrons. (Note that oxidizing agents do not have to contain oxygen.)
percolate: to move slowly through the pores of a rock.
porous: a material containing many small holes or cracks. Quite often the pores are connected, and liquids, such as water or oil, can move through them.
precipitate: tiny solid particles formed as a result of a chemical reaction between two liquids or gases.
prospector: a person who is exploring for geologically rich deposits of metals and gemstones.
reaction: the recombination of two substances using parts of each substance to produce new substances.
resin: resins are natural or synthetic polymers.They can be molded into solid objects or spun into thread.
saturated: a state in which a liquid can hold no more of a substance. If any more of the substance is added, it will not dissolve.
solution: a mixture of a liquid and at least one other substance (e.g., saltwater). Mixtures can be separated by physical means, for example, by evaporation
and cooling.
stable: able to exist without changing into another substance.
weather: a term used by Earth scientists and derived from “weathering.” It means to react with water and gases of the environment.
weathering: the slow natural processes that break down rocks and reduce them to small fragments either by mechanical or chemical means.