CAMPBELL BIOLOGY 9TH AP CHAPTERS 1–56
COMPLETE STUDY GUIDE 2026
◉ Element. Answer: Substance that cannot be broken down to other
substances through chemical reactions. Each has a symbol. 92
occurring in nature.
◉ Compound. Answer: Substance consisting of two or more
different elements combined in a fixed ratio.
*Characteristics different than those of its elements
◉ CHON. Answer: 4 elements essential to life
◉ Trace Elements. Answer: Required by an organism only in minute
quantities.
◉ Atom. Answer: Smallest unit of matter that retains the properties
of an element. Composed of subatomic particles. Mostly empty
space.
◉ Subatomic particles. Answer: Neutrons, protons, electrons. Make
up atoms.
,◉ Proton. Answer: One unit of positive charge. Approximately one
dalton. Located in nucleus.
◉ Electron. Answer: One unit of negative charge. Located outside of
nucleus.
◉ Atomic Nucleus. Answer: Dense core packed with protons and
neutrons.
◉ Neutrons. Answer: Electrically neutral. Approximately one dalton.
◉ Atomic Number. Answer: The number of protons (which is unique
to that element) and written as a subscript to left of element symbol.
Also tells us number of electrons since P=E if atom is neutral
◉ Mass Number. Answer: Sum of the protons and the neutrons. An
approximation of the atomic mass.
◉ Isotopes. Answer: Same number of protons, but different number
of neutrons and therefore different mass. Same element.
◉ Radioactive Isotope. Answer: One in which the nucleus decays
spontaneously, giving off particles and energy. Can decay to a
different element. Have useful applications.
, ◉ Energy. Answer: Capacity to cause change
◉ Potential Energy. Answer: Energy matter possesses because of its
location or structure. Electrons have this based on distance from
nucleus.
◉ Electron Shells. Answer: Where electrons are found, each with
characteristic average distance and energy level. Electrons can
change these by absorbing or losing energy.
◉ Valence Electrons. Answer: Electrons in the outermost shell.
◉ Chemical Bonds. Answer: The attraction that holds atoms
together during an interaction.
◉ Covalent Bond. Answer: Sharing of a pair of valence electrons by
two atoms.
◉ Molecule. Answer: Two or more atoms held together by covalent
bonds.
◉ Single Bond. Answer: One pair of shared electrons.
COMPLETE STUDY GUIDE 2026
◉ Element. Answer: Substance that cannot be broken down to other
substances through chemical reactions. Each has a symbol. 92
occurring in nature.
◉ Compound. Answer: Substance consisting of two or more
different elements combined in a fixed ratio.
*Characteristics different than those of its elements
◉ CHON. Answer: 4 elements essential to life
◉ Trace Elements. Answer: Required by an organism only in minute
quantities.
◉ Atom. Answer: Smallest unit of matter that retains the properties
of an element. Composed of subatomic particles. Mostly empty
space.
◉ Subatomic particles. Answer: Neutrons, protons, electrons. Make
up atoms.
,◉ Proton. Answer: One unit of positive charge. Approximately one
dalton. Located in nucleus.
◉ Electron. Answer: One unit of negative charge. Located outside of
nucleus.
◉ Atomic Nucleus. Answer: Dense core packed with protons and
neutrons.
◉ Neutrons. Answer: Electrically neutral. Approximately one dalton.
◉ Atomic Number. Answer: The number of protons (which is unique
to that element) and written as a subscript to left of element symbol.
Also tells us number of electrons since P=E if atom is neutral
◉ Mass Number. Answer: Sum of the protons and the neutrons. An
approximation of the atomic mass.
◉ Isotopes. Answer: Same number of protons, but different number
of neutrons and therefore different mass. Same element.
◉ Radioactive Isotope. Answer: One in which the nucleus decays
spontaneously, giving off particles and energy. Can decay to a
different element. Have useful applications.
, ◉ Energy. Answer: Capacity to cause change
◉ Potential Energy. Answer: Energy matter possesses because of its
location or structure. Electrons have this based on distance from
nucleus.
◉ Electron Shells. Answer: Where electrons are found, each with
characteristic average distance and energy level. Electrons can
change these by absorbing or losing energy.
◉ Valence Electrons. Answer: Electrons in the outermost shell.
◉ Chemical Bonds. Answer: The attraction that holds atoms
together during an interaction.
◉ Covalent Bond. Answer: Sharing of a pair of valence electrons by
two atoms.
◉ Molecule. Answer: Two or more atoms held together by covalent
bonds.
◉ Single Bond. Answer: One pair of shared electrons.
