alkaline: An adjective that describes a chemical that produces hydroxide ions (OH-) in a solution. These solutions are also referred to as basic — as in the opposite of acidic — and have a pH above 7.
aquifer: Rock that can hold pools of groundwater. The term can also be applied to those underground pools of water.
atmosphere: The envelope of gases surrounding Earth, another planet or a moon.
basalt: A type of black volcanic rock that tends to be very dense (unless volcanic eruptions seeded it with lots of air pockets).
bond: (in chemistry) A semi-permanent attachment between atoms — or groups of atoms — in a molecule. It’s formed by an attractive force between the participating atoms. Once bonded, the atoms will work as a unit. To separate the component atoms, energy must be supplied to the molecule as heat or some other type of radiation.
carbon: A chemical element that is the physical basis of all life on Earth. Carbon exists freely as graphite and diamond. It is an important part of coal, limestone and petroleum, and is capable of self-bonding, chemically, to form an enormous number of chemically, biologically and commercially important molecules. (in climate studies) The term carbon sometimes will be used almost interchangeably with carbon dioxide to connote the potential impacts that some action, product, policy or process may have on long-term atmospheric warming.
carbon dioxide: (or CO2) A colorless, odorless gas produced by all animals when the oxygen they inhale reacts with the carbon-rich foods that they’ve eaten. Carbon dioxide also is released when organic matter burns (including fossil fuels like oil or gas). Carbon dioxide acts as a greenhouse gas, trapping heat in Earth’s atmosphere. Plants convert carbon dioxide into oxygen during photosynthesis, the process they use to make their own food.
cement: To glue two materials together with a binder that hardens into a rigid solid, or the viscous glue used to affix the two materials. (in construction) A finely ground material used to bind sand or bits of ground rock together in concrete. Cement typically starts out as a powder. But once wet, it becomes a mudlike sludge that hardens as it dries.
chemical: A substance formed from two or more atoms that unite (bond) in a fixed proportion and structure. For example, water is a chemical made when two hydrogen atoms bond to one oxygen atom. Its chemical formula is H2O. Chemical also can be an adjective to describe properties of materials that are the result of various reactions between different compounds.
chemical bonds: Attractive forces between atoms that are strong enough to make the linked elements function as a single unit. Some of the attractive forces are weak, some are very strong. All bonds appear to link atoms through a sharing of — or an attempt to share — electrons.
chemical reaction: A process that involves the rearrangement of the molecules or structure of a substance, as opposed to a change in physical form (as from a solid to a gas).
chemistry: The field of science that deals with the composition, structure and properties of substances and how they interact. Scientists use this knowledge to study unfamiliar substances, to reproduce large quantities of useful substances or to design and create new and useful substances. (about compounds) Chemistry also is used as a term to refer to the recipe of a compound, the way it’s produced or some of its properties. People who work in this field are known as chemists. (in social science) A term for the ability of people to cooperate, get along and enjoy each other’s company.
climate change: Long-term, significant change in the climate of Earth. It can happen naturally or in response to human activities, including the burning of fossil fuels and clearing of forests.
decarbonization: A term for a deliberate move away from polluting technologies, activities and energy sources — ones that spew carbon-based greenhouse gases (such as carbon dioxide and methane) into the atmosphere. The goal is to reduce the amount of carbon-based gases that contribute to climate change.
development: (in engineering) The growth or change of something from an idea to a prototype.
electricity: A flow of charge, usually from the movement of negatively charged particles, called electrons.
electron: A negatively charged particle, usually found orbiting the outer regions of an atom; also, the carrier of electricity within solids.
engineer: A person who uses science and math to solve problems. As a verb, to engineer means to design a device, material or process that will solve some problem or unmet need.
ethanol: A type of alcohol, also known as ethyl alcohol, that serves as the basis of alcoholic drinks, such as beer, wine and distilled spirits. It also is used as a solvent and as a fuel (often mixed with gasoline, for instance).
filter: (n.) Something that allows some materials to pass through but not others, based on their size or some other feature. (v.) The process of screening some things out on the basis of traits such as size, density, electric charge. (in physics) A screen, plate or layer of a substance that absorbs light or other radiation or selectively prevents the transmission of some of its components.
flammable: Something that can burn (go up in flames) easily.
formate: The generic term for any salt or ester of formic acid, an oxidized version of one fatty acid. (An ester is a carbon-based compound made by replacing the hydrogen of some acid by any of several specific types of organic groups. Many fats and essential oils are natural types of esters created from fatty acids.)
fossil fuel: Any fuel — such as coal, petroleum (crude oil) or natural gas — that has developed within the Earth over millions of years from the decayed remains of bacteria, plants or animals.
fuel: Any material that will release energy during a controlled chemical or nuclear reaction. Fossil fuels (coal, natural gas and petroleum) are a common type that liberate their energy through chemical reactions that take place when heated (usually to the point of burning).
fuel cell: A device that converts chemical energy into electrical energy. The most common fuel is hydrogen, which emits only water vapor as a byproduct.
geological: Adjective to describe things related to Earth’s physical structure and substance, its history and the processes that act on it. People who work in this field are known as geologists.
global warming: The gradual increase in the overall temperature of Earth’s atmosphere due to the greenhouse effect. This effect is caused by increased levels of carbon dioxide, chlorofluorocarbons and other gases in the air, many of them released by human activity.
hydrogen: The lightest element in the universe. As a gas, it is colorless, odorless and highly flammable. It’s an integral part of many fuels, fats and chemicals that make up living tissues. It’s made of a single proton (which serves as its nucleus) orbited by a single electron.
innovation: (v. to innovate; adj. innovative) An adaptation or improvement to an existing idea, process or product that is new, clever, more effective or more practical.
lye: The common name for a solution of sodium hydroxide (NaOH). Lye is often mixed with vegetable oils or animal fats and other ingredients to make solid bars of soap.
materials scientist: A researcher who studies how the atomic and molecular structure of a material is related to its overall properties. Materials scientists can design new materials or analyze existing ones. Their analyses of a material’s overall properties (such as density, strength and melting point) can help engineers and other researchers select materials that are best suited to a new application.
molecule: An electrically neutral group of atoms that represents the smallest possible amount of a chemical compound. Molecules can be made of single types of atoms or of different types. For example, the oxygen in the air is made of two oxygen atoms (O2), but water is made of two hydrogen atoms and one oxygen atom (H2O).
pollutant: A substance that taints something — such as the air, water, our bodies or products. Some pollutants are chemicals, such as pesticides. Others may be radiation, including excess heat or light. Even weeds and other invasive species can be considered a type of biological pollution.
potent: An adjective for something (like a germ, poison, drug or acid) that is very strong or powerful.
renewable: An adjective for resources that can be endlessly replaced (such as water, green plants, sunlight and wind). This is in contrast to non-renewable resources, for which there is a finite supply — one that can essentially be used up. These include petroleum (and other fossil fuels) or relatively rare elements and minerals.
salt: A compound made by combining an acid with a base (in a reaction that also creates water). The ocean contains many different salts — collectively called “sea salt.” Common table salt is a made of sodium and chlorine.
sodium bicarbonate: Also known as baking soda, this white, chemical powder occurs naturally. Its formula is NaHCO3. It also has been used as a natural product to extinguish small electrical and grease fires. When ingested, it can help settle acid stomachs. Indeed, it is the main ingredient of many antacids sold in grocery stores.
sodium hydroxide: A chemical (NaOH) that is used in the production of paper and soap, among other uses. It is used to make solutions more basic (alkaline).
solar: Having to do with the sun or the radiation it emits. It comes from sol, Latin for sun.
solid: Firm and stable in shape; not liquid or gaseous.
system: A network of parts that together work to achieve some function. For instance, the blood, vessels and heart are primary components of the human body’s circulatory system. Similarly, trains, platforms, tracks, roadway signals and overpasses are among the potential components of a nation’s railway system. System can even be applied to the processes or ideas that are part of some method or ordered set of procedures for getting a task done.
technology: The application of scientific knowledge for practical purposes, especially in industry — or the devices, processes and systems that result from those efforts.
transition: The boundary where one thing (paragraphs, ecosystems, life stage, state of matter) changes or converts into another. Some transitions are sharp or abrupt. Others slowly or gradually morph from one condition or environment to another.