Elements & Compounds Packet #5

Review Matter Mixtures Homogenous Mixture Solution Heterogeneous Mixture Pure Substances Found within Mixtures Compounds Elements {Compounds when separated} Elements

Elements Element is the simplest form of matter that has a unique set of properties *Elements are composed of atoms that have the same atomic number.

Compounds A compound is a substance that contains two or more elements chemically combined in a fixed proportion. Remember that a compound can be considered a pure substance. Compound can be broken down into elements

Representation Elements & Compounds

Representation Chemists use chemical symbols to represent elements and chemical formulas to represent compounds. Each element is represented by one-letter or two-letter chemical symbols. The first letter always capitalized The second letter always lowercase

Chemical Reactions

Introduction Chemical Property The ability if a substance to undergo a specific chemical change is called a chemical property. When iron combines with oxygen, rust is produced. During a chemical change, the composition of matter always changes.

Chemical Reactions A chemical change is also called a chemical reaction. Chemical reaction When one or more substances change into one or more new substances.

Parts of a Chemical Reaction There are “two parts” of a chemical reaction. Reactant The substance that is present at the start if the chemical reaction. Product The substance produced by the chemical reaction.

Important Note During any chemical reaction, the mass of the products is always equal to the mass of the reactants. Falls under the law of conservation of mass In any physical change or chemical reaction, mass is conserved. Mass is neither created nor destroyed.

Review