Chapter 3 : Molecules, Compounds and Chemical Equations

• CH 4 and O 2 are the reactants, and CO 2 and H 2 Oare the products• the (g) after the formulas tells us the state of thechemical• the number in front of each substance tells us thenumbers of those molecules in the reactionCH 4 (g) + 2 O 2 (g) CO 2 (g) + 2 H 2 O(g)called the coefficients• this equation is balanced, meaning that there areequal numbers of atoms of each element on thereactant and product sidesto obtain the number of atoms of an element, multiply thesubscript by the coefficientChemical Reactions