Occluded Front - A type of front formed when a cold front overtakes a warm front, lifting the warm air mass off the ground. It typically results in complex weather patterns and precipitation.
Organic Chemistry - the study of the structure, properties, composition, reactions, and preparation of carbon-containing compounds.
Organic Compound - compounds containing carbon and hydrogen that are either found in or were made by living or once living organisms.
Organic Elements - chemical elements, primarily carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur, that are the building blocks of all living organisms and form the basis of organic compounds
Organism - an individual animal, plant, or single-celled life form.
Paleontologist - a scientist who specializes in the study of life forms that existed in previous geologic periods, as represented by their fossils
Pangaea - The name given to the super-continent containing all of Earth's landmass that broke apart about 200 million years ago.
Penumbra - The shadow cast by the Earth or the Moon during a partial eclipse
Period – a horizontal row (left to right) in the periodic table.
Periodic Table – a chart that organizes information about all of the known elements according to their properties.
Phenotype - The physical appearance of an organism that is determined by its genotype.
Photosynthesis - the biological process by which sunlight is used to convert carbon dioxide and water into glucose and oxygen.
Physical Change - A process that changes the appearance of a substance without changing what it is made of
Plasma - a state of matter that occurs when a gas is energized to the point that its electrons are no longer attached to a specific atomic nucleus.
Pollution - The contamination of the air, water and soil by harmful substances.
Polymers - large molecules made by bonding (chemically linking) a series of smaller building blocks called monomers.
Precipitate - A solid substance that forms at the bottom of a liquid solution during a chemical reaction.
Precipitation - Any form of water, liquid or solid, that falls from the atmosphere and reaches the ground. This includes rain, snow, sleet, and hail.
Prefix - a small group of letters added to the beginning of a word to change its meaning
Probability - The chance that an event can happen.
Producers - Organisms in an ecosystem that create their own food through the process of photosynthesis. They are the building blocks of all food webs.
Proteins - An organic compound made up mostly of carbon, hydrogen, oxygen and nitrogen. They are the building blocks of body structures like muscle and skin as well as enzymes which help speed up chemical reactions.
Protein Synthesis - The process of using the DNA code to make RNA and build proteins at the ribosome.
Proton - A positively charged particle found in the nucleus of an atom. The number of protons determines the identity of the atom. A proton has a mass of 1 amu (atomic mass unit)
Punnett square - A chart that looks at the combination of traits an organism can possibly inherit.
Pure Substance - substances that are made up of only one kind of particle and have a fixed or constant structure.