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• SYNTHESIS (OR ____) REACTION: a chemicalreaction in which smaller molecules combine to form a larger one. As shown below, two or more reactants (A and B) combine to form a product (AB).

  Combination
• ____ REACTION: a chemical reaction in which acompound (AB) breaks apart into two or more products (A and B). It is the oppositeof a synthesis reaction. Most decomposition reactions need an outside source ofenergy to take place.

  Decomposition
• ____ ____ (OR REPLACEMENT) REACTION:a chemical reaction in which a reactant (A) takes the place of some component of a compound (BC). In doing so, a new compound (AC) is made, and a separate product (B) is released.

  Single Displacement
• SINGLE DISPLACEMENT (OR ____) REACTION:a chemical reaction in which a reactant (A) takes the place of some component of acompound (BC). In doing so, a new compound (AC) is made, and a separate product (B)is released. Replacement
• ____ ____ (OR REPLACEMENT)REACTION: a chemical reaction between two compounds, AB andCD, in which component of one reactant trades places with component of another reactant. The elements are rearranged to form two or more different compound products, AD and CB.

  Double displacement
• When a chemical reaction occurs, it can be described by a chemical equation, which uses chemical symbols and formulas to describe a reaction.
• The law of conservation of matter states that matter cannot be created or destroyed, although it may be changed.
• According to the law of conservation of matter, the mass of the reactants must equal the mass of the products, with the exception of nuclear reactions.
• The law of conservation of mass states that the mass of the reactants must equal the mass of the products, with the exception of nuclear reactions.
• A balanced chemical equation demonstrates conservation of atoms.
• If a hydrogen atom goes into a reaction, it has to appear somewhere in the products of the reaction.
• The number in front of the chemical formula is called a coefficient.
• Antoine Lavoisier proposed the first version of the law of conservation of mass.
• Antoine Lavoisier named oxygen.
• The numbers of molecules such as O2 are called subscripts.
• Substances that release hydrogen ions (H+) when dissolved in water are acids.
• Acids often donate H+ ions to bases.
• Acids dissociate (break down) into ions in solution, making them able to conduct electricity.
• Bases are substances that either release hydroxide ions (OH_ ) when dissolved in water or that accept H+ ions from acids.
• Alkalis are a type of base made of ionic salts of an alkali metal (Group1) or an alkaline earth metal (Group2).
• All alkalis are bases, but not all bases are alkalis.