Sciece Flashcards
Acid
A ion that releases hydrogen ion when dissolved in water; has a pH
If less than 7.
Absolute zero
Approximately -273° C; the lowest possible temperature
Algae
Simple one celled plant like organism found in water or damp places; includes sea wee, pond scum, etc.
Alloy
A substance composed if two or more metals
Atmosphere
The layer of air surrounding earth
Atmospheric pressure
The pressure exerted by the atmosphere on every part of Earth’s surface; approximately 10 newtons per square centimeter
Atom
The smallest part of an element that is recognizable as that element.
Barometer
A instrument that measures atmospheric pressure.
Base
A compound that releases hydroxide ions in water; has a pH of more than 7; is sometimes called an alkali
Boiling point
The temperature at which additional thermal energy causes a substance to change from a liquid to a vapor
Calorie
A quantity of heat energy; the amount needed to raise the temperature of one gram of water 1° C.
Carbohydrate
An organic compound-like sugar or starch that contains carbon, hydrogen, and oxygen in the ratio of 1:2:1; the human body’s main source of energy
Carcinogen
A cancer causing agent
Carnivore
Meat water
Catalyst
A substance that speeds up a chemical reaction without being changed by the reaction
Cell
The lowest-level structure of any living organism that can perform all the functions of life, including reproduction
Chlorophyll
The main pigment in plants that captures light energy during photosynthesis
Compound
A substance composed of two or more chemically bonded elements
Concentration
The exact amount of substance dissolved in a given amount of solvent; refers to a solution
Condensation
The process whereby a decrease in energy causes vapor particles to return to a liquid phase
