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Science-1
Vocab from Science Journal 9/30/2013
Term | Definition |
---|---|
Symbol | one or two letters used to represent an element |
Chemical Formula | a combination of symbols and numbers that represent the number and types of elements (atoms) present in a compound |
Subscript | a small number to the right of a symbol that is written below the normal line of letters to show how many atoms of an element are present in a substance; no subscript means there is only one atom present |
Chemical Reaction | when substances interact to form one or more new substances with different properties than the original substances |
Chemical Equation | a combination of chemical formulas used to describe what happens in a chemical reaction; the equation identifies the reactants and resulting product |
Coefficient | a number written in front of a chemical formula to show how many molecules of that substance are present |
Reactant | formulas written on the left side of the arrow symbol (-->)are the starting substances in a chemical reaction |
Product | formulas written on the right side of the arrow symbol (-->) are the new substances formed in a chemical reaction |
Yields | an arrow symbol that show a reaction has taken place; the reactants have reacted to produce a new substance (the product) |
Compound | a substance composed of two or more elements chemically combined and in a definite proportion |
Physical Change | a change in which the characteristics of a substance are only changed physically and the original properties stay the same |
Chemical Change | a change in which a substance (or substances) is changed into one or more new substances with different properties than the original substances |
Law of Conservation of Mass | matter is not created or destroyed, only changed; the number of atoms in the reactants must be equal to the number of atoms in the product |
Precipitate | a solid that forms as a result of a chemical reaction; it will fall to the bottom of the container |