Biology 1202 Midterm Exam Questions and Answers| New Update with 100%
Correct Answers
What is matter and what is it composed of? Any substance that has mass and occupies
space. CHON
Carbon (18%)
Hydrogen(9.5%)
Oxygen (65%)
Nitrogen(3.3%)
What is an element? pure substance that consists entirely of one type of atom
What is an atomic number? the number of protons in an atom
What is atomic mass? the number of protons plus the number of neutrons
What are electrons? Negatively charged particles, revolve around the nucleus. They travel
with opposite spin (up vs down)
Are filled orbitals stable? Yes they are, unlike partially filled orbitals that are less stable.
What are valence electrons? electrons in the outermost energy level
What are isotopes? Atoms of the same element with different numbers of neutrons
How is the periodic table arranged? Grouping atoms based on valence electrons
What are inert atoms? Have outer valence level filled (noble gases)
, What are reactive atoms? Do not have outer level filled and want to make a octet to achieve
the most stable state.
What is electronegativity? a measure of the tendency of an atom to attract a bonding pair of
electrons
What makes an atom more electronegative? More protons in the nucleus, greater the
positive field the more drawn electrons are.
What is an ionic bond? A chemical bond that's formed when an atom transfers and electron
to another Atom
What is a covalent bond? A chemical bond formed when two or atoms share electrons.
(create an octet)
What is an nonpolar covalent bond? Sharing of valence electrons between atoms means
that the orbitals of each atom will overlap, atoms have equal electronegativity and are
hydrophobic.
What is an Polar Covalent Bond? Sharing of valence electrons between atoms means that
the orbitals of each atom will overlap, atoms have unequal electronegativity and are
hydrophillic.
What are hydrogen bonds? a weak bond between two molecules resulting from an
electrostatic attraction between a proton in one molecule and an electronegative atom in the
other.
What are Van der Waals forces? a slight attraction that develops between the oppositely
charged regions of nearby molecules, develop between nonpolar molecules.
Correct Answers
What is matter and what is it composed of? Any substance that has mass and occupies
space. CHON
Carbon (18%)
Hydrogen(9.5%)
Oxygen (65%)
Nitrogen(3.3%)
What is an element? pure substance that consists entirely of one type of atom
What is an atomic number? the number of protons in an atom
What is atomic mass? the number of protons plus the number of neutrons
What are electrons? Negatively charged particles, revolve around the nucleus. They travel
with opposite spin (up vs down)
Are filled orbitals stable? Yes they are, unlike partially filled orbitals that are less stable.
What are valence electrons? electrons in the outermost energy level
What are isotopes? Atoms of the same element with different numbers of neutrons
How is the periodic table arranged? Grouping atoms based on valence electrons
What are inert atoms? Have outer valence level filled (noble gases)
, What are reactive atoms? Do not have outer level filled and want to make a octet to achieve
the most stable state.
What is electronegativity? a measure of the tendency of an atom to attract a bonding pair of
electrons
What makes an atom more electronegative? More protons in the nucleus, greater the
positive field the more drawn electrons are.
What is an ionic bond? A chemical bond that's formed when an atom transfers and electron
to another Atom
What is a covalent bond? A chemical bond formed when two or atoms share electrons.
(create an octet)
What is an nonpolar covalent bond? Sharing of valence electrons between atoms means
that the orbitals of each atom will overlap, atoms have equal electronegativity and are
hydrophobic.
What is an Polar Covalent Bond? Sharing of valence electrons between atoms means that
the orbitals of each atom will overlap, atoms have unequal electronegativity and are
hydrophillic.
What are hydrogen bonds? a weak bond between two molecules resulting from an
electrostatic attraction between a proton in one molecule and an electronegative atom in the
other.
What are Van der Waals forces? a slight attraction that develops between the oppositely
charged regions of nearby molecules, develop between nonpolar molecules.
