ECU CHEM 1120 Ch. 3–5 Exam 2 Prep – Chemistry Review Guide & Practice
Problems
ionic bond - correct answer ✔✔metal and nonmetal
atoms give and take electrons to complete octets
covalent bond - correct answer ✔✔nonmetal and nonmetal (Groups 4A-7A)
atoms share electrons to complete octets
compound - correct answer ✔✔contains atoms of different elements attached to each other via
chemical bonds
atoms are electrically neutral - correct answer ✔✔same number of protons and electrons
overall electrical charge - correct answer ✔✔if an atom gains or loses an electron the number of
electrons and protons are no longer equal, so they now have an overall electrical charge
positive charge - correct answer ✔✔(+) results from loss of electron
negative charge - correct answer ✔✔(-) results from gaining of electron
valence shells - correct answer ✔✔look at the number of groups (IA-VIIIA) to determine how
many valence electrons they have
,octet rule - correct answer ✔✔every atom wants to feel like it has 8 valence electrons, so it can
feel like it is a noble gas
Na+ // Cl- - correct answer ✔✔Na only has 1 valence electron, so it loses 1 (thus making it seem
like Ne) to make it feel like a noble gas
Cl only has 7 valence electrons, so it gains 1 (thus making it seem like Ar) to make it feel like a
noble gas
ionization energy - correct answer ✔✔the energy required to remove 1 electron from an atoms
valence shell
the lower the ionization energy the easier it is to lose an electron, and favors positive ion
formation
i.e. Mg has a 2+ charge, but in order to fill the octet rule it loses those 2 electrons
electron affinity - correct answer ✔✔the energy released on adding 1 electron to an atoms
valence shell
the higher the electron affinity the easier it is to gain an electron, and favors negative ion
formation
i.e. S has a 2- charge, but in order to fill the octet rule it gains those 2 electrons
ionization energy and electron affinity - correct answer ✔✔both increase as you go from left to
right on the periodic table and from the bottom to the top
charged ions - correct answer ✔✔metals tend to form + charged ions
, nonmetals tend to form - charged ions
Group 1a-3a charges - correct answer ✔✔Group 1: 1+ (just + when attached to an element)
Group 2: 2+
Group 3: 3+
electrons in these groups lose the amount of electrons that the charge suggests
cation - correct answer ✔✔forms positive ions (positive charge)
positive ions - correct answer ✔✔formed by metals
lose electron
fewer electrons than protons
negative ions - correct answer ✔✔formed by nonmetals
gain electron
more electrons than protons
anion - correct answer ✔✔forms negative ions (negative charge)
group 5a-7a - correct answer ✔✔Group 5: 3-
Group 6: 2-
Group 7: 1- (just - when attached to an element)
electrons in these groups gain the amount of electrons that the charge suggests
Problems
ionic bond - correct answer ✔✔metal and nonmetal
atoms give and take electrons to complete octets
covalent bond - correct answer ✔✔nonmetal and nonmetal (Groups 4A-7A)
atoms share electrons to complete octets
compound - correct answer ✔✔contains atoms of different elements attached to each other via
chemical bonds
atoms are electrically neutral - correct answer ✔✔same number of protons and electrons
overall electrical charge - correct answer ✔✔if an atom gains or loses an electron the number of
electrons and protons are no longer equal, so they now have an overall electrical charge
positive charge - correct answer ✔✔(+) results from loss of electron
negative charge - correct answer ✔✔(-) results from gaining of electron
valence shells - correct answer ✔✔look at the number of groups (IA-VIIIA) to determine how
many valence electrons they have
,octet rule - correct answer ✔✔every atom wants to feel like it has 8 valence electrons, so it can
feel like it is a noble gas
Na+ // Cl- - correct answer ✔✔Na only has 1 valence electron, so it loses 1 (thus making it seem
like Ne) to make it feel like a noble gas
Cl only has 7 valence electrons, so it gains 1 (thus making it seem like Ar) to make it feel like a
noble gas
ionization energy - correct answer ✔✔the energy required to remove 1 electron from an atoms
valence shell
the lower the ionization energy the easier it is to lose an electron, and favors positive ion
formation
i.e. Mg has a 2+ charge, but in order to fill the octet rule it loses those 2 electrons
electron affinity - correct answer ✔✔the energy released on adding 1 electron to an atoms
valence shell
the higher the electron affinity the easier it is to gain an electron, and favors negative ion
formation
i.e. S has a 2- charge, but in order to fill the octet rule it gains those 2 electrons
ionization energy and electron affinity - correct answer ✔✔both increase as you go from left to
right on the periodic table and from the bottom to the top
charged ions - correct answer ✔✔metals tend to form + charged ions
, nonmetals tend to form - charged ions
Group 1a-3a charges - correct answer ✔✔Group 1: 1+ (just + when attached to an element)
Group 2: 2+
Group 3: 3+
electrons in these groups lose the amount of electrons that the charge suggests
cation - correct answer ✔✔forms positive ions (positive charge)
positive ions - correct answer ✔✔formed by metals
lose electron
fewer electrons than protons
negative ions - correct answer ✔✔formed by nonmetals
gain electron
more electrons than protons
anion - correct answer ✔✔forms negative ions (negative charge)
group 5a-7a - correct answer ✔✔Group 5: 3-
Group 6: 2-
Group 7: 1- (just - when attached to an element)
electrons in these groups gain the amount of electrons that the charge suggests
