All ACT words for 6-2

O1- Atom: The smallest part of an element that is recognizable as that element

O2-Acid: compound with a pH less than 7

O3-Base: compound with a pH greater than 7 (synonym:alkali)

O4-CalorieA quantity of heat energy; the amount needed to raise the temperature of one gram of water 1° C

O5-Cell: The lowest-level structure of any living organism that can perform all the functions of life, including reproduction

O6-Carnivore: Meat-eater

O7-Condensation: The process whereby a decrease in energy causes vapor particles to return to a liquid phase

O8-Chlorophyll: the main pigment in plants that captures light energy during photosynthesis

O9-Compound: a substance composed of two or more chemically bonded elements

O10-Conductor: a material that allows heat or electricity to flow through it with minimal resistance

O11-Control Group: a sample or group in which no variables are tested. The control serves as a basis for comparison to the tested group.

Example: 1. Testing how watering affects plants- test group gets different amounts of water. The Control group will not get water.- Scientists will compare the control group to the group that was tested ( got water in this case)

EX: same height for egg drop

O12-Control variable: a variable that stays constant in an experiment, allowing the effect of another variable to be measured

O13-DensityIn a physics sense, the amount of mass per unit volume; in a more general sense, the quantity per unit area or volume

O14-DNA: Nucleic acid in the cells of an organism; contains the genes of an organism and transmits these to future generations

O15-Ecological succession: a sequence of changes in the plant or animal life of a region or habitat

O16-Electron: a negatively charged part of the atom

O17-Element:A substance consisting of exactly one type of atom

O18-Erosion: wearing away, typically by running water or wind

O19-Evaporation: the changing of liquid into gas

O20-Fossil: The preserved remains of a very old organism

O21-Habitat: the area of the ecosystem where a plant or animal naturally lives

O22-Herbivore: an animal that eats only plants

O23-Hypothesis: A statement that is a proposed explanation of a scientific phenomenon or event ( Testable)

O24-Insulator: a substance that blocks the flow of heat or electricity

O25-Kinetic energy: the energy of an object in motion

O26-Molecule: The smallest unit of a chemical compound

O27-Parasite: an organism that invades another organism and feed off that organism (host)

O28-Photosynthesis: the process in which plants use the sun's energy to convert carbon dioxide and water into glucose

O29-Symbiosis: A close relationship between two organisms that is mutually exclusive

O30-AtmosphereThe layer of air surrounding Earth