Which of the following changes is chemical rather than physical? a. Water is boiled c. Glass is shattered b. Aluminum foil is crumpled d. Wood is burned

Each substance written to the right of the arrow in a chemical equation is a ______ a. Reactant c. Precipitate b. Product d. Catalyst

When the following chemical reaction is balanced, what number is placed before NH3? N2 + 3H2 __ NH3 a. 1 c. 3 b. 2 d. 4

A substance that speeds up chemical reactions without changing itself is a(n) a. Inhibitor c. Enzyme b. Catalyst d. Prohibitor

What type of reaction is FeS + 2HCl FeCl2 + H2S? a. A Synthesis Reaction b. A Decomposition Reaction c. A Single-Replacement Reaction d. A Double-Replacement Reaction

A chemical equation that shows the same number and kind of atom on both sides of the equation is said to be a. Balanced b. Unbalanced c. An incomplete reaction d. A replacement reaction

Anything that has mass and takes up space is considered a. Matter c. Chemistry b. Energy d. Endothermic

What happens when chemical bonds break and new bonds form? a. A physical change b. A chemical reaction c. Matter is destroyed d. Surface area increases

CaCO3 represents a chemical a. Symbol c. Equation b. Formula d. Reaction

A shorter, easier way to show chemical reactions, using symbols instead of words, is called a a. Chemical Equation c. Symbol b. Chemical Formula d. Subscript

The substances listed on the left side of a chemical equation are the a. Products c. Precipitates b. Coefficients d. Reactants

Which of the following is a balanced chemical equation? a. H2O2 H2O + O2 b. 2 Fe2O3 + 3C 4Fe + 3CO2 c. SO2 + O2 + 2H2O 4H2SO4 d. 2Mg + HCl MgCl2 + H2

A chemical reaction that absorbs energy in the form of heat is described as a. Endothermic c. Combustion b. Exothermic d. Unbalanced

The minimum amount of energy that has to be added to start a reaction is the a. Exothermic Reaction c. Activation Energy b. Endothermic Reaction d. Chemical Energy

A material used to decrease the rate of a chemical reaction is a(n) a. Inhibitor c. Enzyme b. Catalyst d. Fuel

In a chemical equation, numbers often appear in front of a chemical formula. These numbers tell you the a. Number of atoms in each molecule in the reaction b. Number of elements in the reaction c. Number of molecules or atoms of each substance in the reaction d. Number of molecules in each atom in the reaction

Chemicals that act as biological catalysts by speeding up reactions in living things are a. Inhibitors c. Fuels b. Enzymes d. Reactants

The number placed below an element’s symbol a. Subscript c. Reactant b. Coefficient d. Product

Which of the following chemical equations is balanced? a. 3Ca + O2 3CaO2 b. 3Ca + 2O2 5CaO2 c. Ca + 2O2 2CaO2 d. Ca + O2 CaO2

Which of the following is an example of a chemical reaction? a. Ice melting in a glass of water b. Paper turning soft when wet c. Salt crystals forming as sea water evaporates d. Leaves changing colors in the fall

How many Carbon atoms are in this glucose molecule? C6H12O6 a. 3 c. 12 b. 6 d. 24

How many sodium (Na) ions are in this molecule? 7Na3PO4 a. 3 c. 21 b. 7 d. 28

What occurs when water freezes? a. A physical change b. A chemical reaction c. A chemical bond d. A diatomic molecule

What is the force that holds atoms together called? a. A chemical solution b. A chemical mixture c. A chemical reaction d. A chemical bond

Which is the product in this chemical formula? N + O2 NO2 a. N c. O2 b. O d. NO2

Which of these uses coefficients correctly to balance this equation? N2 + H2 NH3 a. N2 + 3H2 2NH3 b. 2N2 + 2H2 4NH3 c. N2 + H2 NH3 d. 3N2 + 4H2 6NH3

Which of the following states the law of conservation of mass? a. Atoms are rearranged in a chemical reaction, and some join new molecules b. Two compounds combine to form a new compound with different properties c. Mass cannot be created nor destroyed in a chemical reaction d. Energy is neither created nor destroyed in a chemical reaction

How many oxygen atoms are present in the reactant in this chemical equation? 4Fe + 3O2 2Fe2O3 a. 2 c. 4 b. 3 d. 6

Which of the following is an example of a diatomic molecule a. NaCl c. Mg b. O2 d. CaCl2

How many atoms are present in the formula CaCO3? a. Three c. Five b. Four d. Six

If a chemical symbol in a chemical formula has no subscript, it means a. The chemical symbol is written without any numbers b. The element has no charge c. The chemical is listed last in the formula d. Only one atom of the element is in the molecule

Which phrase describes what happens to atoms in a chemical reaction? a. Sometimes lost, never rearranged b. Sometimes lost, gained, or rearranged c. Never lost or gained, just rearranged d. Lost or gained, never rearranged

What must be done for a chemical equation to be balanced? a. All molecules must be counted b. All chemicals must be equal c. All atoms must be counted d. All atoms must be discounted

Which of the following shows an exothermic reaction? a. 2Na + Cl2 2NaCl + energy b. 2H2 + O2 2H2O c. 2H2O + energy 2H2 + O2 d. 6CO2 + 6H2O + energy C6H12O6 + 6O2

What happens in an endothermic reaction? a. Energy is destroyed b. Energy is released c. Energy is created d. Energy is taken in

Which of the following chemical reactions illustrates a decomposition reaction? a. 2H2O 2H2 + O2 b. 4H2 + O2 2H2O c. 6CO2 + 6H2O + energy C6H12O6 + 6O2 d. 4KI + 2Cl 4KCl + 2I2

Which of the following chemical reactions illustrates a Synthesis reaction? a. 2H2O 2H2 + O2 b. 4H2 + O2 2H2O c. 6CO2 + 6H2O + energy C6H12O6 + 6O2 d. 4KI + 2Cl 4KCl + 2I2

Which of the following chemical reactions illustrates a Single-Replacement reaction? a. 2H2O 2H2 + O2 b. 4H2 + O2 2H2O c. 6CO2 + 6H2O + energy C6H12O6 + 6O2 d. 4KI + 2Cl 4KCl + 2I2

Which of the following chemical reactions illustrates a Endothermic reaction? a. 2H2O 2H2 + O2 b. 4H2 + O2 2H2O c. 6CO2 + 6H2O + energy C6H12O6 + 6O2 d. 4KI + 2Cl 4KCl + 2I2