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acidic An adjective for materials that contain acid. These materials often are capable of eating away at some minerals such as carbonate, or preventing their formation in the first place.
algae Single-celled organisms, once considered plants (they aren’t). As aquatic organisms, they grow in water. Like green plants, they depend on sunlight to make their food.
Arctic A region that falls within the Arctic Circle. The edge of that circle is defined as the northernmost point at which the sun is visible on the northern winter solstice and the southernmost point at which the midnight sun can be seen on the northern summer solstice.
Arctic Circle The northernmost point at which the sun is visible on the northern winter solstice and the southernmost point at which the midnight sun can be seen on the northern summer solstice.
atmosphere The envelope of gases surrounding Earth or another planet.
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.
bacteria ( singular: bacterium ) Single-celled organisms. These dwell nearly everywhere on Earth, from the bottom of the sea to inside other living organisms (such as plants and animals).
bog A type of wetland that forms peat from the accumulation of dead plant material — often mosses.
carbon The chemical element having the atomic number 6. It 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.
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.
chromatography Separation and detection of chemical compounds as a result of their having traveled at different rates according to their different attractions to the matter that carries them (such as a flowing liquid or gas).
climate The weather conditions that typically exist in one area, in general, or over a long period.
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.
decay The process (also called “rotting”) by which a dead plant or animal gradually breaks down as it is consumed by bacteria and other microbes. (for radioactive materials) The process whereby a radioactive isotope — which means a physically unstable form of some element — sheds energy and subatomic particles. In time, this shedding will transform the unstable element into a slightly different but stable element. For instance, uranium-238 (which is a radioactive, or unstable, isotope) decays to radium-222 (also a radioactive isotope), which decays to radon-222 (also radioactive), which decays to polonium-210 (also radioactive), which decays to lead-206 — which is stable. No further decay occurs. The rates of decay from one isotope to another can range from timeframes of less than a second to billions of years.
ecology A branch of biology that deals with the relations of organisms to one another and to their physical surroundings. A scientist who works in this field is called an ecologist.
ecosystem A group of interacting living organisms — including microorganisms, plants and animals — and their physical environment within a particular climate. Examples include tropical reefs, rainforests, alpine meadows and polar tundra.
element (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.
environment The sum of all of the things that exist around some organism or the process and the condition those things create. Environment may refer to the weather and ecosystem in which some animal lives, or, perhaps, the temperature and humidity (or even the placement of components in some electronics system or product).
forensics (adj. forensic) The use of science and technology to investigate and solve crimes.
genetic Having to do with chromosomes, DNA and the genes contained within DNA. The field of science dealing with these biological instructions is known as genetics. People who work in this field are geneticists.
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.
graduate student Someone working toward an advanced degree by taking classes and performing research. This work is done after the student has already graduated from college (usually with a four-year degree).
greenhouse A light-filled structure, often with windows serving as walls and ceiling materials, in which plants are grown. It provides a controlled environment in which set amounts of water, humidity and nutrients can be applied — and pests can be prevented entry.
Greenland The world’s largest island, Greenland sits between the Arctic Ocean and North Atlantic. Although it is technically part of North America (sitting just east of Northern Canada), Greenland has been linked more politically to Europe. Indeed, Vikings arrived in Greenland around the 10th century, and for a time the island was a colony of Denmark. In June 2009, Greenland became an independent nation. Ice covers roughly 80 percent of Greenland. Indeed, the Greenland ice sheet is the world’s largest. If its frozen water were to melt, it could raise sea levels around the world by 6 meters (about 20 feet). Although this is the 12th biggest nation (based on surface area), Greenland averages the fewest people per square kilometer of its surface area.
mass spectrometry A technique used to determine the chemical makeup of a source material.
microbe Short for microorganism. A living thing that is too small to see with the unaided eye, including bacteria, some fungi and many other organisms such as amoebas. Most consist of a single cell.
microbiology The study of microorganisms, principally bacteria, fungi and viruses. Scientists who study microbes and the infections they can cause or ways that they can interact with their environment are known as microbiologists.
microbe A living thing that is too small to see with the unaided eye, including bacteria, some fungi and many other organisms such as amoebas. Most consist of a single cell.
mineral Crystal-forming substances that make up rock, such as quartz, apatite or various carbonates. Most rocks contain several different minerals mish-mashed together. A mineral usually is solid and stable at room temperatures and has a specific formula, or recipe (with atoms occurring in certain proportions) and a specific crystalline structure (meaning that its atoms are organized in regular three-dimensional patterns). (in physiology) The same chemicals that are needed by the body to make and feed tissues to maintain health.
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).
moss A small, flowerless green plant that lacks true roots. It tends to grow as carpets or rounded cushions in damp habitats. It can reproduce asexually, through fragmentation, or by means of spores released from stalked capsules.
native Associated with a particular location; native plants and animals have been found in a particular location since recorded history began. These species also tend to have developed within a region, occurring there naturally (not because they were planted or moved there by people). Most are particularly well adapted to their environment.
nutrient A vitamin, mineral, fat, carbohydrate or protein that a plant, animal or other organism requires as part of its food in order to survive.
organic (in chemistry) An adjective that indicates something is carbon-containing; a term that relates to the chemicals that make up living organisms. (in agriculture) Farm products grown without the use of non-natural and potentially toxic chemicals, such as pesticides.
organism Any living thing, from elephants and plants to bacteria and other types of single-celled life.
Pacific The largest of the world’s five oceans. It separates Asia and Australia to the west from North and South America to the east.
peat Largely decomposed plant material that develops in the absence of oxygen within a water-saturated site, such as a bog. When dried out, peat can be burned as a low-grade fuel.
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).
radioactive An adjective that describes unstable elements, such as certain forms (isotopes) of uranium and plutonium. Such elements are said to be unstable because their nucleus sheds energy that is carried away by photons and/or and often one or more subatomic particles. This emission of energy is by a process known as radioactive decay.
radiocarbon dating A process to determine the age of material from a once-living object. It is based on comparing the relative proportion, or share, of the carbon-12 to carbon-14. This ratio changes as radioactive carbon-14 decays and is not replaced.
rainforest Dense forest rich in biodiversity found in tropical areas with consistent heavy rainfall.
ratio The relationship between two numbers or amounts. When written out, the numbers usually are separated by a colon, such as a 50:50. That would mean that for every 50 units of one thing (on the left) there would also be 50 units of another thing (represented by the number on the right).
tundra A cold, usually lowland area in far northern regions. The subsoil is permanently frozen. In summer, a tundra’s top layer of soil thaws and can support low-growing mosses, lichens, grasses, shrubs and trees (some only a few centimeters high).
wetland As the name implies, this is a low-lying area of land either soaked or covered with water much of the year. It hosts plants and animals adapted to live in, on or near water.
