atmosphere: The envelope of gases surrounding Earth, another planet or a moon.

atom: The basic unit of a chemical element. Atoms are made up of a dense nucleus that contains positively charged protons and uncharged neutrons. The nucleus is orbited by a cloud of negatively charged electrons.

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 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.

carbon monoxide: A toxic gas whose molecules include one carbon atom and one oxygen atom. (The “mono” in “monoxide” is a prefix from Greek that means “one”.) One common source: fossil-fuel burning.

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.

chlorine: A chemical element with the scientific symbol Cl. It is sometimes used to kill germs in water. Compounds that contain chlorine are called chlorides.

climate: The weather conditions that typically exist in one area, in general, or over a long period.

concentration: (in chemistry) A measurement of how much of one substance has been dissolved into another.

dairy: Containing milk or having to do with cows or milk. Or a building or company in which milk is prepared for distribution and sale.

diffuse: adj.) To be spread out thinly over a great area; not concise or concentrated. (v) To spread light or to broadly release some substance through a liquid (such as water or air) or through some surface (such as a membrane).

dilute: To make something thinner or less concentrated by adding a liquid to it.

disinfect: To clean an area by killing dangerous infectious organisms, such as disease-causing bacteria.

dissolve: To turn a solid into a liquid and disperse it into that starting liquid. (For instance, sugar or salt crystals, which are solids, will dissolve into water. Now the crystals are gone and the solution is a fully dispersed mix of the liquid form of the sugar or salt in water.)

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.

element: A building block of some larger structure. (in chemistry) Each of more than one hundred substances for which the smallest unit of each is a single atom. Examples include hydrogen, oxygen, carbon, lithium and uranium.

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.

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.

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.

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.

green: (in chemistry and environmental science) An adjective to describe products and processes that will pose little or no harm to living things or the environment.

greenhouse gas: A gas that contributes to the greenhouse effect by absorbing heat. Carbon dioxide is one example of a greenhouse gas.

hydrochloric acid: A strong (potent) and corrosive acid formed when hydrogen chloride gas dissolves into water. The human gut produces a dilute solution of this to break down foods.

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.

landfill: A site where trash is dumped and then covered with dirt to reduce smells. If they are not lined with impermeable materials, rains washing through these waste sites can leach out toxic materials and carry them downstream or into groundwater. Because trash in these facilities is covered by dirt, the wastes do not get ready access to sunlight and microbes to aid in their breakdown. As a result, even newspaper sent to a landfill may resist breakdown for many decades.

LED: (short for light emitting diode) Electronic components that, as their name suggests, emit light when electricity flows through them. LEDs are very energy-efficient and often can be very bright. They have lately been replacing conventional lights for home and commercial lamps.

livestock: Animals raised for meat or dairy products, including cattle, sheep, goats, pigs, chickens and geese.

manure: Feces, or dung, from farm animals. Manure can be used to fertilize land.

methane: A hydrocarbon with the chemical formula CH4 (meaning there are four hydrogen atoms bound to one carbon atom). It’s a natural constituent of what’s known as natural gas. It’s also emitted by decomposing plant material in wetlands and is belched out by cows and other ruminant livestock. From a climate perspective, methane is 80 times more potent than carbon dioxide is in trapping heat in Earth’s atmosphere, making it a very important greenhouse gas.

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).

natural gas: A mix of gases that developed underground over millions of years (often in association with crude oil). Most natural gas starts out as 50 to 90 percent methane, along with small amounts of heavier hydrocarbons, such as propane and butane.

permafrost: Soil that remains frozen for at least two consecutive years. Such conditions typically occur in polar climates, where average annual temperatures remain close to or below freezing.

physical: (adj.) A term for things that exist in the real world, as opposed to in memories or the imagination. It can also refer to properties of materials that are due to their size and non-chemical interactions (such as when one block slams with force into another).

quash: To completely suppress, destroy, neutralize or extinguish.

radical: (in chemistry) A molecule having one or more unpaired outer electrons. Radicals readily take part in chemical reactions. The body is capable of making radicals as one means to kill cells, and thereby rid itself of damaged cells or infectious microbes.

reactive: (in chemistry) The tendency of a substance to take part in a chemical process, known as a reaction, that leads to new chemicals or changes in existing chemicals.

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: A soft, silvery metallic element that will interact explosively when added to water. It is also a basic building block of table salt (a molecule of which consists of one atom of sodium and one atom of chlorine: NaCl). It is also found in sea salt.

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.

ultraviolet: A portion of the light spectrum that is close to violet but invisible to the human eye.

ventilation: A system that supplies a room with fresh air or processes that move air around and between different rooms.


Please enter your comment!
Please enter your name here