Biological processes are rooted in chemistry, so its important to develop a basic understanding of the elements (the simplest forms of matter) and how they bond to form compounds. Living organisms are primarily made of the elements oxygen, carbon, hydrogen, and nitrogen, as well as other elements in trace amounts. Molecules form when atoms bond together in a particular structure, while compounds are made from elements in a fixed ratio. Elements are made of atoms, and atoms are made of protons, neutrons (which determine the isotopes), and electrons (which play a big role in chemistry through their valence shells). Bonds are generally either covalent or ionic. Avogadros number is used to calculate molecular mass and molar concentration, as well as the amount of reactants and products in a chemical reaction.
are composed of atoms. Atoms are made up of protons, neutrons and
can be found at different energy levels. The particular energy
levels that electrons spend most their time at are described as
electron shells. The valence shell is the outermost electron shell
in an atom.
bonds are formed when atoms share electron pairs.
bonds are the result of an electron pair being more strongly
attracted to one atom in the bond than another. Nonpolar bonds occur
when an electron pair is equally attracted to both atoms forming the
An ionic bond is the attraction between
positively charged ions, called cations, and negatively charged
ions, called anions.
hydrogen bond is formed when a hydrogen atom covalently bound to one
electronegative atom is also attracted to another electronegative
undergo reactions by forming or breaking bonds. The initial
substances involved in the reaction are called reactants; the set of
substances resulting from the reaction are the products.
mole (mol) = 6.02 x 1023.
The molecular mass is the mass that contains one mol of the
substance. The molarity of a solution is its concentration in moles
of solute per liter of solution.
Elements, Compounds, and Chemical Bonds
Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.
The book and CD package include two full length practice exams that are presented with all questions answered and explained. The author also presents detailed reviews of all test topics and includes multiple-choice and free-response questions with answers at the end of each topic's chapter.
This book includes a review of the AP Biology exam format and scoring, proven strategies for answering multiple-choice questions, and hints for tackling the essay questions. The practice tests include answers and explanations and there is also proven test-taking strategies for both the multiple choice and essay parts.