“water decomposes to form hydrogen gas and oxygen gas” H 2 O (l) -> H 2 (g) + O 2 (g) 2 H 2 O (l) -> 2 H 2 (g) + O 2 (g) Can you guess which tube holds the hydrogen? 1. Change words to symbols to form a “skeleton” equation. 1. Add coefficients to balance the equation, conserving atoms on both sides of the equation.

“nitrogen gas combines with hydrogen gas to form ammonia gas” Fritz Haber N 2 (g) + H 2 (g) -> NH 3 (g) N 2 (g) + 3H 2 (g) -> 2NH 3 (g) 1. Change words to symbols to form a “skeleton” equation. 1. Add coefficients to balance the equation, conserving atoms on both sides of the equation.

“solid potassium chlorate (KClO 3 ) decomposes to form solid potassium chloride and oxygen gas” KClO 3 (s) -> KCl (s) + O 2 (g) 2KClO 3 (s) -> 2KCl (s)+ 3O 2 (g) Did you remember to “check charges” on potassium chloride? K +1 and Cl -1 = KCl

“bauxite ore Al(OH) 3 decomposes into solid aluminum oxide and water when heated” Al(OH) 3 (s) -> Al 2 O 3 (s) + H 2 O (l) 2Al(OH) 3 (s) -> Al 2 O 3 (s) + 3H 2 O (l) Al +3 and O -2 form Al 2 O 3