Campbell's Biology Chapter 2 Flashcards

220187165	neutron	a subatomic particle that has no charge and that is located in the nucleus of an atom
220187166	hydrogen bond	weak chemical bond formed by the attraction of positively charged hydrogen atoms to other negatively charged atoms
220187167	salt	sodium chloride NaCl
220187168	covalent bond	a chemical bond that involves sharing a pair of electrons between atoms in a molecule
220187169	atom	(physics and chemistry) the smallest component of an element having the chemical properties of the element
220187170	electronegativity	(chemistry) the tendency of an atom or radical to attract electrons in the formation of an hydrogen bond
220187171	matter	that which has mass and occupies space
220187172	polar covalent bond	a covalent bond in which electrons are not shared equally
220187173	double covalent bond	a bond in which two atoms share two pairs of electrons
220187174	temperature	the intensity of heat
220187175	solution	a liquid consisting of a homogeneous mixture of 2 or more substances
220187176	ionic bond	a chemical bond in which one atom loses an electron to form a positive ion and the other atom gains to electron to form a negative ion
220187177	chemical bond	an electrical force linking atoms
220187178	element	any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter
220187179	heat	a form of energy that is transferred by a difference in temperature
220187180	buffer	an ionic compound that resists changes in its pH
220187181	cohesion	an attraction between molecules of the same substance
220187182	solute	the dissolved substance in a solution
220187183	acid precipitation	precipitation, such as rain, sleet, or snow, that contains a high concentration of acids, often because of the pollution of the atmosphere
220187184	atomic weight	the number of protons plus the number of neutrons
220187185	proton	a stable particle with positive charge equal to the negative charge of an electron
220187186	electron	an elementary particle with negative charge
220187187	pH scale	measurement system used to indicate the concentration of hydrogen ions (H+) in solution; ranges from 0 to 14
220187188	reactant	a chemical substance that is present at the start of a chemical reaction
220187189	nonpolar covalent bond	a covalent bond in which the bonding electrons are shared equally by the bonded atoms, resulting in a balanced distribution of electrical charge
220187190	polar molecule	a molecule in which the charges are unevenly distributed
220187191	product	a chemical substance formed as a result of a chemical reaction
220187192	mass number	the sum of the number of neutrons and protons in an atomic nucleus
220187193	trace element	An element indispensable for life but required in extremely minute amounts.
220187194	acid	a substance that increases the hydrogen ion concentration of a solution
220187195	surface tension	a measure of how difficult it is to stretch or break the surface of a liquid
220187196	solvent	a liquid substance capable of dissolving other substances
220187197	base	a compound that accepts H+ ions and removes them from solution
220187198	molecule	two or more atoms held together by covalent bonds
220187199	chemical reaction	a process leading to chemical changes in matter
220187200	electron shell	an energy level representing the distance of an electron from the nucleus of an atom
220187201	atomic number	number of protons in an atom
220187202	nucleus	the center of an atom containing protons and neutrons
220187203	isotope	a variant form of an element
220187204	ion	an atom with an electrical charge resulting from gain or loss of an electron
220187205	radioactive isotope	an isotope with a decayed nucleus giving off energy