AFOQT (Physical Science) Q&A VERIFIED TEST

AFOQT (Physical Science) Q&A VERIFIED TEST The lowest possible temperature - ANSWER Absolut Zero The pressure exerted by the gases in the air. units of measurement are kilopascals, atmospheres, millimeters of mercury, and Torr - ANSWER atmospheric Pressure Pressure is 100 kPa, 1atm, 760 mm Hg or 760 Torr - ANSWER standard atmospheric pressure the smallest particle of an element a nucleus and its surrounding electrons. - ANSWER Atom the mass of an atom measured in atomic mass units (amu). an atomic mass unit is equal to one-twelfth of the atom of carbon-12. atomic mass is now more generally used instead of atomic weight. Example: the atomic mass of chlorine is about 35amu. - ANSWER atomic mass also known as proton number, it is the number of electrons or the number of protons in an atom. example: the atomic number of gold is 79. - ANSWER atomic number a common term used to mean the average molar mass of an element. this is the mass per mole of atoms. Ex: the atomic weight of chlorine is about 35g/mol - ANSWER atomic weight the temperature at which a substance undergoes a phase change from a liquid to a gas. - ANSWER boiling point. a temperature scale on which the freezing point of water is at 0 degrees and the normal boiling point at standard atmospheric pressure is 100 degrees. - ANSWER celsius scale a change between two of the three states of matter, solid, liquid and gas. example when water evaporates t changes from a liquid to a gaseous state. - ANSWER change of state. a chemical consisting of two or more elements chemically bonded together. example: calcium can combine with carbon and oxygen to make calcium carbonate a compound of all three elements. - ANSWER compound the formation of a liquid from a gas. this is a change of state, also called a phase change. - ANSWER condensation the exchange of heat (heat conduction) by contact with another object, or allowing the flow of electrons (electrical conduction) - ANSWER conduction the exchange of heat energy with the surroundings produced by the flow of a fluid due to being heated or cooled. - ANSWER convection the way that a radioactive element changes into another element due to loss of was through radiation. Example: uranium 238 decays with the loss of an alpha particle to form thorium 234. - ANSWER decay the mass per unit volume - ANSWER density the slow mixing of one substance with another until the two substances are evenly mixed. mixing occurs because of differences in concentration within the mixture. _______ works rapidly with gases, very slowly with liquids. - ANSWER diffusion to break down a substance in a solution without causing a reaction - ANSWER dissolve the energy produced by an electrochemical cell and measured by the voltage or electromotive force. - ANSWER electrical potential a tiny, negatively charged particle that is part of an atom. the flow of electrons through a solid material such as a wire produces an electric current. - ANSWER electron a substance that cannot be decomposed into simpler substance by chemical means. examples: calcium, iron, gold - ANSWER element a substance which when a shock is applied to it, decomposes very rapidly, releasing a very large amount of heat and creating a large volume of gases as a shock wave. - ANSWER explosive able to flow either liquid or a gas - ANSWER fluid the temperature at which a substance undergoes a phase change from a liquid to a solid. it is the same temperature as the melting point. - ANSWER freezing point. waves of radiation produced as a nucleus of a radioactive element rearranges itself into a tighter cluster of protons and neutrons. _______________ carry enough energy to damage living cells. - ANSWER gamma rays a form of matter in which the molecules form no definite shape, and are free to move about to uniformly fill any vessel they are put in. a gas can easily be compressed into a much smaller volume. - ANSWER gas a vertical colu