Flashcards in this deck (46)

• What is the main focus of Chapter 2 in Campbell's Biology?

  The Chemical Context of Life
  biology chemistry
• What do wood ants use to ward off enemies?

  Formic acid
  biology insects
• What is matter?

  Anything that takes up space and has mass
  science matter
• What is an element?

  A substance that cannot be broken down by chemical reactions
  chemistry elements
• What is a compound?

  A substance consisting of two or more elements in a fixed ratio
  chemistry compounds
• What percentage of natural elements are essential for life?

  20–25%
  biology elements
• Which four elements make up 96% of living matter?

  Carbon, hydrogen, oxygen, nitrogen
  biology elements
• What are trace elements?

  Elements required in minute quantities by organisms
  biology elements
• What is an atom?

  The smallest unit of matter that retains the properties of an element
  chemistry atoms
• What are the three subatomic particles?

  Neutrons, protons, electrons
  chemistry subatomic
• What charge do neutrons have?

  No electrical charge
  chemistry subatomic
• What charge do protons have?

  Positive charge
  chemistry subatomic
• What charge do electrons have?

  Negative charge
  chemistry subatomic
• Where do neutrons and protons reside in an atom?

  In the atomic nucleus
  chemistry atoms
• What is an element's atomic number?

  The number of protons in its nucleus
  chemistry atomic_number
• What is an element's mass number?

  The sum of protons plus neutrons in the nucleus
  chemistry mass_number
• What are isotopes?

  Atoms of an element that differ in the number of neutrons
  chemistry isotopes
• What happens to radioactive isotopes?

  They decay spontaneously, giving off particles and energy
  chemistry radioactivity
• What is radiometric dating?

  Measuring the ratio of isotopes to calculate age
  science dating
• What does the half-life of an isotope represent?

  The fixed rate at which a parent isotope decays into a daughter isotope
  science half-life
• What is energy?

  The capacity to cause change
  science energy
• What is potential energy in matter?

  Energy due to location or structure.
  energy potential
• What is the tendency of matter regarding potential energy?

  Move toward the lowest state of potential energy.
  energy matter
• How do electrons differ in potential energy?

  Based on their distance from the nucleus.
  electrons energy
• Can changes in electron potential energy occur in arbitrary amounts?

  No, only in fixed steps.
  electrons energy
• What determines the chemical behavior of an atom?

  Distribution of electrons in electron shells.
  chemistry atoms
• What does the periodic table show?

  Electron distribution for each element.
  chemistry periodic_table
• What corresponds to the left-to-right sequence in the periodic table?

  Sequential addition of electrons and protons.
  chemistry periodic_table
• What are valence electrons?

  Electrons in the outermost shell.
  electrons valence
• What determines an atom's chemical behavior?

  Number of valence electrons.
  chemistry valence
• What are chemically inert elements?

  Elements with a full valence shell.
  chemistry inert
• What is an orbital?

  3D space where an electron is found 90% of the time.
  electrons orbitals
• How many electrons can occupy a single orbital?

  No more than 2 electrons.
  electrons orbitals
• What depends on chemical bonding between atoms?

  Formation and function of molecules and ionic compounds.
  chemistry bonding
• What can atoms with incomplete valence shells do?

  Share or transfer valence electrons.
  chemistry valence
• What are chemical bonds?

  Attractions that hold atoms close together.
  chemistry bonds
• What is a covalent bond?

  Sharing of a pair of valence electrons by two atoms.
  chemistry covalent
• What does a molecule consist of?

  Two or more atoms held by covalent bonds.
  chemistry molecules
• What is a single covalent bond?

  Sharing of one pair of valence electrons.
  chemistry covalent
• What is a double covalent bond?

  Sharing of two pairs of valence electrons.
  chemistry covalent
• What is a structural formula?

  Notation to represent atoms and bonding.
  chemistry structure
• What is bonding capacity called?

  The atom's valence.
  chemistry valence
• What is electronegativity?

  An atom's attraction for electrons in a covalent bond.
  chemistry electronegativity
• What happens to shared electrons in a covalent bond?

  More electronegative atoms pull them toward themselves.
  chemistry covalent
• What is electronegativity?

  An atom's attraction for the electrons in a covalent bond.
  chemistry electronegativity
• What happens when an atom is more electronegative?

  It pulls shared electrons more strongly toward itself.
  chemistry electronegativity