Module 6 Exam Review - Chemistry in Biology

Which of the following best describes atoms?

• Atoms are made of three particles called electrons, neutrons, and protons.

• Atoms are hard, solid balls of matter that are the smallest known particles.

• Atoms are composed of electrical charges that are made only of energy.

• Atoms are made of uniform spheres called a nucleus surrounded by electrons.

Identify the reactants in the following chemical equation:

Cd(NO₃)₂ + H₂S --> CdS + 2HNO₃

• Cd(NO₃)₂ + H₂S

• CdS + 2HNO₃

• 2HNO₃

• CdS

Identify the products in the following chemical equation:

Cd(NO₃)₂ + H₂S --> CdS + 2HNO₃

• CdS + 2HNO₃

• Cd(NO₃)₂ + H₂S

• H₂S

• CdS

To develop a product that warms people's hands, would you use an exothermic or endothermic reaction? Why?

• Exothermic; that way the reaction will release heat.

• Endothermic; that way the reaction will absorb heat.

• Exothermic; that way the reaction will absorb heat.

• Endothermic; that way the reaction will release heat.

Why is the active site of an enzyme important to enzyme activity?

• It raises the activation energy of a reaction.

• It allows the enzyme to interact with a large variety of substrates.

• It allows the enzyme to catalyze very specific reactions.

• It allows an endothermic reaction to run as an exothermic reaction.

How do enzymes affect a chemical reaction, making it easier to occur?

• They reduce the activation energy.

• They raise the activation energy.

• They make the reaction exothermic.

• They make the reaction endothermic.

Which of the following is not a property of water?

• It is cohesive.

• It is adhesive.

• It is a good solvent.

• It combusts.

How are water molecules in a rain drop held together?

• attraction between negative charges

• van der Waals forces

• ionic bonds

• attraction between positive charges

Which is true in a covalent bond?

• The bond is caused by van der Waals forces.

• The bond forms when electrons are donated.

• The bond forms between ions.

• The bond forms when electrons are shared.

A covalent bond is a weak electrostatic bond formed by the attraction of opposite charges between a hydrogen atom and an oxygen, fluorine, or nitrogen atom.

• true

• false