Science 10 - Unit A - Atomic Model Notes

chemical change {Ans: A change in matter that produces one or more new substances}Combustion {Ans: Chemical reaction that occurs when O2 reacts rapidly with a substance to form a new product and give off energy (burning)}decomposition reaction {Ans: a reaction in which a single compound breaks down to form two or more simpler substances}covalent bond {Ans: Formed when two or more non-metals share electrons}biochemical reactions {Ans: Can be exothermic and endothermic}valence electrons {Ans: Electrons on the outermost energy level of an atom}Base {Ans: Compounds that dissolve in water who's solution has a pH higher than 7.}pH scale {Ans: measurement scale for an acid and base}Polyatomic elements {Ans: Elements that do not exist as singles. They quickly pair up to form molecules.}energy level {Ans: A region of an atom in which electrons of the same energy are likely to be found.}covalent bond {Ans: Atoms in a molecule are joined by covalent bonds. A chemical bond formed when two atoms share electrons.}indicators {Ans: a simple test to measure whether the substance is acid or a base}Endothermic {Ans: Energy is absorbed (reactant side) you feel the cool.}pH {Ans: Measure