Bio 1124 Midterm EXAM 1 Test
Questions And All Correct Answers
2025.
Element - Answer A substance that cannot be broken down to any other substance by
chemical reaction
Atom - Answer Smallest unit of matter that retains the properties of an element
Proton - Answer Subatomic particle with a positive charge located in the nucleus; amount
determines which element the atom is
Neutron - Answer Subatomic particle with a neutral charge located in the nucleus; used to
figure the atomic mass of an atom
Electron - Answer Subatomic particle with a negative charge that moves around the nucleus in
an orbital
Atomic Number - Answer The amount of protons in an atom; unique number that determines
which element the atom is
Mass Number - Answer The total mass of the atom; # of protons plus # of neutrons
Orbital - Answer Three dimensional space where an electron is found 90% of the time;
component of an electron shell
Valence Shell - Answer The outermost electron shell; determines the chemical reactivity of an
element
Valence Electron - Answer Electrons in the outermost electron shell; only electrons used
during chemical reactions
6 Most abundant elements in human body? - Answer Oxygen, Carbon, Hydrogen, Nitrogen,
Calcium, Phosphorus
, Carbon - Answer Atomic number 6
Hydrogen - Answer Atomic number 1
Max number of orbitals and electrons in first electron shell? - Answer 1s-orbital with 2
electrons
Max number of orbitals and electrons in second electron shell? - Answer 2s-orbital with 2
electrons; Three 2p-orbitals with 2 electrons each for a total of 8 electrons
Max number of orbitals and electrons in third electron shell? - Answer 3s-orbital with 2
electrons; three 3p-orbitals with 2 electrons each; five 3d-orbital with 2 electrons each; total 18
electrons
Molecule - Answer Two or more atoms held together by covalent bonds
Covalent Bond - Answer The sharing of a pair of valence electrons by two atoms
Double Covalent Bond - Answer The sharing of two pairs of valence electrons between two
atoms
Nonpolar Covalent bond - Answer When two atoms of the same electronegativity have an
equal attraction to the electrons in a covalent bond
Polar Covalent Bond - Answer A covalent bond between atoms that differ in electronegativity.
The shared electrons are pulled closer to the more electronegative atom, making it slightly
negative and the other atom slightly positive
Electronegativity - Answer The attraction of a particular atom for the electrons in its covalent
bond
Ionic Bond - Answer A chemical bond resulting from the attraction between oppositely
charged ions
Questions And All Correct Answers
2025.
Element - Answer A substance that cannot be broken down to any other substance by
chemical reaction
Atom - Answer Smallest unit of matter that retains the properties of an element
Proton - Answer Subatomic particle with a positive charge located in the nucleus; amount
determines which element the atom is
Neutron - Answer Subatomic particle with a neutral charge located in the nucleus; used to
figure the atomic mass of an atom
Electron - Answer Subatomic particle with a negative charge that moves around the nucleus in
an orbital
Atomic Number - Answer The amount of protons in an atom; unique number that determines
which element the atom is
Mass Number - Answer The total mass of the atom; # of protons plus # of neutrons
Orbital - Answer Three dimensional space where an electron is found 90% of the time;
component of an electron shell
Valence Shell - Answer The outermost electron shell; determines the chemical reactivity of an
element
Valence Electron - Answer Electrons in the outermost electron shell; only electrons used
during chemical reactions
6 Most abundant elements in human body? - Answer Oxygen, Carbon, Hydrogen, Nitrogen,
Calcium, Phosphorus
, Carbon - Answer Atomic number 6
Hydrogen - Answer Atomic number 1
Max number of orbitals and electrons in first electron shell? - Answer 1s-orbital with 2
electrons
Max number of orbitals and electrons in second electron shell? - Answer 2s-orbital with 2
electrons; Three 2p-orbitals with 2 electrons each for a total of 8 electrons
Max number of orbitals and electrons in third electron shell? - Answer 3s-orbital with 2
electrons; three 3p-orbitals with 2 electrons each; five 3d-orbital with 2 electrons each; total 18
electrons
Molecule - Answer Two or more atoms held together by covalent bonds
Covalent Bond - Answer The sharing of a pair of valence electrons by two atoms
Double Covalent Bond - Answer The sharing of two pairs of valence electrons between two
atoms
Nonpolar Covalent bond - Answer When two atoms of the same electronegativity have an
equal attraction to the electrons in a covalent bond
Polar Covalent Bond - Answer A covalent bond between atoms that differ in electronegativity.
The shared electrons are pulled closer to the more electronegative atom, making it slightly
negative and the other atom slightly positive
Electronegativity - Answer The attraction of a particular atom for the electrons in its covalent
bond
Ionic Bond - Answer A chemical bond resulting from the attraction between oppositely
charged ions
