Science Terms A-C Flashcards
acceleration
the rate that velocity changes per unit of time and the direction it changes in, computed from the change in velocity divided by the change in time. Common units are meters per second squared (m/s2).
** acceleration due
to gravity**
the acceleration of an object that is only acted on by the force of the Earth’s gravity. This value is given the symbol g, and near the surface of the Earth it has a value of approximately 9.8 m/s2. The direction of acceleration due to gravity is downward.
accuracy
the closeness of an experimental measurement to the accepted or theoretical value
acid
a substance that is a proton donor. The pH of an acid is less than 7.
analysis
a stage in the scientific method where patterns of the observations are made
aqueous solution
a solution in which the solvent is water
arteries
the vascular tissues that carry blood away from the heart
astronomy
the study of the planets, stars, and space
atom
the smallest structure that has the properties of an element. Atoms contain positively charged protons and uncharged neutrons in the nucleus. Negatively charged electrons orbit around the nucleus.
ATP
(Adenosine Triphosphate) a chemical that is considered to be the “fuel” or energy source for an organism
atria
the chambers of the heart that receive blood
** base **
a substance that is a proton acceptor. The pH of a base is greater than 7.
calibration
the examination of the performance of an instrument in an experiment whose outcomes are known, for the purpose of accounting for the inaccuracies inherent in the instrument in future experiments whose outcomes are not known
capillaries
vascular tissues that receive blood from the arterioles and releases the blood to the venuoles
catalyst
an agent that changes the rate of a reaction, without itself being altered by the reaction
celestial equator
the extension of the Earth’s equator out onto the celestial sphere
** celestial poles**
the extension of the Earth’s north and south poles onto the celestial sphere
celestial sphere
the imaginary sphere which all the stars are viewed as being on for the purposes of locating them
cell membrane
an organelle found in all cells that acts as the passageway through which materials can pass in and out. This organelle is highly selectively permeable, only allowing materials to pass through that it “chooses” chemically.
cell wall
an organelle found primarily in plant cells and fungi cells, and also some bacteria. The cell wall is a strong structure that provides protection, support, and allows materials to pass in and out without being selectively permeable.
centripetal force
the net force that acts to result in the centripetal acceleration. It is not an individual force, but the sum of the forces in the radial direction. It is directed toward the center of the circular motion.
chemical change
a process that involves the formation or breaking of chemical bonds
** chromosome**
an organelle that contains the entire DNA of the organism
component
the part of a vector that lies in the horizontal or vertical direction
compound
a substance composed of more than one element that has a definite composition and distinct physical and chemical properties
concentration
a measure of the amount of solute that is present in a solution. A solution that contains very little solute is called dilute. A solution that contains a relatively large amount of solute is said to be concentrated.
conclusion
the last stage of the scientific method, where explanations are made about why the patterns identified in the analysis section occurred
constellation
an apparent grouping of stars in the sky that is used for identification purposes. These stars are not necessarily near each other in space, since they are not necessarily the same distance from the Earth.
**continental rift **
the region on a continent where new crust is being created, and the plates on either side of the rift are moving apart
**convergent boundary **
a boundary between two of the Earth’s plates that are moving toward each other
**cosmology **
the study of the formation of the universe
**crystal **
a solid in which atoms or molecules have a regular repeated arrangement
**current **
the flow of charge past a point per unit time; current is measured in amperes (A)
**cuticle **
the top layer on a leaf. It is a non-living layer consisting primarily of wax that is produced by the epithelium, a cell layer directly underneath.
**cytoplasm **
a jelly-like substance located in the cell where all of the internal organelles can be found. The cytoplasm consists primarily of water and supports the cell and its organelles.
**cytoskeleton **
organelles that are the internal “bones” of the cell. They exist in thick and thin tubules.
