CHEMICAL REACTIONS

The Basics Reactants Products _________ are the starting materials for a chemical reaction. Reactants _________ are the new chemicals that are made in the reaction. Products Together, the reactants and the products make a ________ ________. chemical reaction Reactants Products

Parts of an equation: reactants – (everything before the arrow) products – (everything after the arrow) ex: 2H2 + O2 2H2O reactants products

CHEMICAL REACTION – _______ that changes one or more _________ into one or more _________________ process substances NEW SUBSTANCES

signs that show a chemical reaction has occurred: 1. A _______________ change occurs permanent color ___ is produced (could be bubbles or an odor!) Gas

precipitate light liquid solid 3. Gives off ______ 4. Forms a ____________ (a ______ is formed from a _______) liquid solid

5. An ____________ or ___________ reaction occurs endothermic exothermic (A Change in Temperature occurs !) absorbs Endothermic – ________ heat (feels _____) cold Exothermic – __________ heat (feels ____) releases hot

The Symbols… Symbol What it means… +  (s) (l) (g) (aq) Used to separate 2 reactants or 2 products  Yields or becomes (s) Substance is in the solid phase (l) Substance is in the liquid phase (g) Substance is in the gas phase (aq) Solution is aqueous (dissolved in water)