Chem Chapter 8
match the reason for the exception to the general trends for electron affinity (EA) to the appropriate group(s) of elements
-EA lower for Group 2A than 1A : added electron in higher energy np orbital, well shielded from the nucleus -EA lower for Group 5A than 4A : added electron placed in an already half-filled np orbital, increasing electron-electron repulsions -Noble gases : electron is added to a (n + 1) orbital; very weakly attracted to the nucleus due to shielding by the core electrons
match each alkali metal or group of alkali metals with the type of oxide each forms on reaction with O2.
-Li : oxides -Na, K, Rb, Cs : oxides and peroxides -K, Rb, Cs: oxides, peroxides, and superoxides
match each Group 6A element correctly to the description of its properties
-O: nonmetal, most common allotrope is a diatomic species -S, Se: nonmetal, exists as a polyatomic species -Te: metalloid, exists as a complex 3D structure -Po: metalloid, radioactive, exists as a complex 3D structure
which of the following options correctly describe the oxidation states of group 4A elements? -only form compounds with a +4 oxidation state -SnO2 is only slightly more stable than SnO -Pb tends to form compounds in which it has a +2 oxidation state -CO is more stable than CO2
-SnO2 is only slightly more stable than SnO -Pb tends to form compounds in which it has a +2 oxidation state
which of the following statements correctly describe effective nuclear charge (Z eff)? -a lower Z eff is due to the loss of a proton from the nucleus -nuclear charge is only lowered by inner electrons -a lower Z eff makes a given electron easier to remove -the effective nuclear charge is lowered by electron-electron repulsion
-a lower Z eff makes a given electron easier to remove -the effective nuclear charge is lowered by electron-electron repulsions
electron affinity increases __________ electron affinity varies little ____________
-across a period -down a group
which of the following statements correctly describe the general characteristics of Group 7A elements? -are all nonmetal -exist as polyatomic species -called the halogen group -anions derived from Group 7A elements have a -1 charge -have large positive electron affinities -have low ionization energies
-are all nonmetal -called the halogen group -anions derived from Group 7A elements have a -1 charge -have large positive electron affinities
which of the following statements correctly describe atomic radii of representative elements? -atomic radii generally decrease down a group -atomic radii of main group elements decrease across a period -atomic radii decrease as the effective nuclear charge (Z eff) decreases -atomic radii generally increase as n increases
-atomic radii of main group elements decrease across a period -atomic radii generally increase as n increases
which of the following options correctly describe the trends in ionization energy? -for any element, second ionization energies are always lower than first ionization energies -atoms with low ionization energies tend to form cations -noble gases have high ionization energies -nonmetals tend to have low ionization energies
-atoms with low ionization energies tend to form cations -noble gases have high ionization energies
which of the following options correctly describe the exceptions to the general trend in ionization energy? -group 3A elements have lower ionization energies than 2A elements -noble gases have unexpectedly low ionization energies -group 3A elements have a single electron in their outermost p subshell that is easier to remove than an s electron in the same shell -group 6A elements have higher ionization energies than group 5A elements -there are no exceptions to the ionization energy trend
-group 3A elements have lower ionization energies than 2A elements -group 3A elements have a single electron in their outermost p subshell that is easier to remove than an s electron in the same shell
which of the following options correctly compares the behavior of hydrogen to Group 1A and Group 7A elements? -hydrogen, like Group 7A, requires only 1 electron to fill its valence shell -hydrogen has the same number of valence electrons as a Group 7A element -hydrogen, like the alkali metals, forms a cation with a +1 charge -hydrogen, unlike the group 7A elements, does not form covalent bonds -hydrogen has the same valence electron configuration as a Group 1A element
-hydrogen, like Group 7A, requires only 1 electron to fill its valence shell -hydrogen, like the alkali metals, forms a cation with a +1 charge -hydrogen has the same valence electron configuration as a Group 1A element
which of the following statements correctly describe the periodic trends in the behavior of metals and nonmetals? -metals have high ionization energies -metallic character increases down a group -nonmetals have high electron affinities -metallic character increases across a period
-metallic character increases down a group -nonmetals have high electron affinities
the atomic radius of an element may differ depending on how it is measured. match each type of radius with the correct description.
-metallic radius : one-half the distance between the centers of two adjacent atoms -diatomic radius : one-half the distance between the centers of atoms in the molecules
which of the following are the most commonly found nitrogen- and phosphorous-containing compounds? -most metallic nitrides (ex: Li3N and Mg3N2) are ionic compounds -nitrogen has a tendency to donate its 5 valence electrons when forming compounds -nitrogen forms many gaseous oxides -phosphorous forms two solid oxides: P4O6 and P4O10
-most metallic nitrides (ex: Li3N and Mg3N2) are ionic compounds -nitrogen forms many gaseous oxides -phosphorous forms two solid oxides: P4O6 and P4O10
match each type of element with the correct trend observed for ionization energies and electron affinities
-noble gases: high IE and low electron affinity -nonmetals: high IE and high electron affinity -metals: low IE and low electron affinity
which of the following options correctly describe the numbering systems used for the periodic table?
-the nonsequential B numbering system is used to acknowledge the similarity in the number of outer electrons for transition and main group elements -the IUPAC has suggested using a system where the groups are numbered from 1-18
which of the following statements correctly describe the changes that occur as we move from left to right across the periodic table? -the number of core electrons increases -the number of valence electrons increases for representative elements -the nuclear charge felt by the outermost electrons decreases -the nuclear charge increase
-the number of valence electrons increases for representative elements -the nuclear charge increases
which of the following statements correctly describe the original periodic table?
-the original periodic table predicted the properties of elements that were not discovered until later -had 66 elements -was developed by Dmitri Mendeleev -some inconsistencies were present in the original periodic table. for example, Ar was listed as in the same group as alkali metals.
which of the following statements correctly describe the types of ions formed by group 3A elements? -B and Al tend to form +3 ions -the stability of cations with a +1 charge increases down group 3A -cations with a +3 charge are equally stable for all group 3A elements -all group 3A elements except Al can form +1 and +3 ions
-the stability of cations with a +1 charge increases down group 3A -all group 3A elements except Al can form +1 and +3 ions
which of the following options correctly describe the group 8A elements? -they're called the halogen group -they exist as diatomic species -they have very low electron affinities -they have low ionization energies -all group 8A elements with n ≥ 2 have filled outer ns and np subshells
-they have very low electron affinities -all group 8A elements with n ≥ 2 have filled outer ns and np subshells
which of the following statements correctly describe the trends in ionic radii? -within an isoelectronic series of anions, species with a charge of -1 have larger ionic radii than species with a charge of -2 -within an isoelectronic series of cations, ionic radius decreases with increasing nuclear charge -ionic radius increases down a group on the periodic table -an anion is larger than its parent atom
-within an isoelectronic series of cations, ionic radius decreases with increasing nuclear charge -ionic radius increases down a group on the periodic table -an anion is larger than its parent atom
the nuclear charge an electron actually experiences is called the _______ nuclear charge (Z eff). this charge is always _________ than the actual nuclear charge since in a many-electron system the electrons _______ each other from the nucleus
effective; smaller; shield
ionization is an _______ process and ionization energy values are therefore _______
endothermic; positive
true or false: physical properties vary predictably across a given period in the periodic table
false - from left to right in the periodic table there is a large variation in physical properties from metals to metalloids to nonmetals. in contrast, down a group of elements with the same state, physical properties vary predictably.
due to the very high ionization energies of noble gases, they will only react with extremely strong oxidizing agents. for this reason, the only two elements that have been observed to form bonds to the noble gases are __________ and __________.
fluorine; oxygen
for main group elements of the periodic table, the _________ number indicates the number of _________
group; valence electrons
the layout of the modern periodic table reflects the fact that, in general, elements in the same group ______
have the same valence electron configuration
for any given element, the second ionization energy will be _________ than the first, and the third ionization energy will be ______ than the second.
higher; higher
both group 1A and group 1B have similar electron configurations but very different reactivities. group 1B elements have _________ ionization energies than group 1A elements, and as a consequence are _______ reactive. this difference in reactivity is due to the _______ shielding of the nucleus by the inner d electrons.
higher; less; incomplete
as electrons are added to an atom, there is a(n) ________ in electron-electron repulsions. this causes an anion of a given element to be _________ than the neutral atom
increase; bigger
metallic behavior tends to _______ down a group in the periodic table and __________ from left to right across a period.
increase; decrease
as we move down a group in the periodic table, both atomic and ionic radii tend to _________. comparisons of ionic radii between groups can only be made if the species are isoelectronic. for an isoelectronic series of ions, cations are ______ than anions.
increase; smaller
the energy required for the complete removal of 1 mol of electrons from 1 mol of gaseous atoms or ions is called __________ energy. for a neutral element this energy is a measure of how easily the element forms an ion with a ________ charge.
ionization; positive
metals in group 3A
lose np electrons first, then the ns electrons
alkali metals have ________ ionization energies, and therefore tend to form ions with a charge of ________
low; +1
Mendeleev's original periodic table ordered elements by atomic ________, whereas the modern periodic table is ordered by atomic _________.
mass; number
calcium reacts _______ vigorously with water than beryllium does, because calcium has ________ metallic character than beryllium
more; greater7
the more tightly an electron is held by the nucleus, the _______ difficult it is to remove and the ______ the ionization energy
more; higher
main group elements that are in the same group of the periodic table have the same __________
valence electron configuration
the energy change associated with the addition of an electron to an atom to form an anion is called the electron _______ of the element
affinity
a species that exhibits both acidic and basic behavior is described as being __________
amphoteric
match each type of electron with its relative shielding effect on an electron at the valence level
core electrons - greater shielding effect other valence electrons - lesser shielding effect
in the alkaline earth metal group, the first and second ionization energies ________ from Be to Ba. these metals therefore tend to form __________; hence the metallic character ______ down the group.
decrease; +2; increases
the metallic character of the elements ________ moving from left to right across the periodic table, causing the corresponding oxides to be _______ acidic moving from left to right.
decreases; more
sulfur forms two different oxides: sulfur ______ (SO2) and the highly acidic sulfur ________ (SO3) that reacts with water to form ________ acid.
dioxide; trioxide; sulfuric
ionization energy and electron affinity both express the general attraction of an atom for ___________
electrons
main group nonmetals
gain electrons to fill the np sublevel
halogens form _____compounds with alkali metals and alkaline earth metals called metal halides. halogens can also form _________ compounds with other halogens or nonmetals from other groups.
ionic; covalent
alkali and alkali earth metals
lose all electrons from ns sublevel
transition metals
lose ns electrons before losing (n-1)d electrons
the alkali metals have ______ ionization energies compared to other elements in the same period, causing them all to be very reactive.
low
the main group element arsenic has an incompletely filled ______ subshell, while the transition metal chromium has an incompletely filled ____ subshell
p; d
for any element in the periodic table, the __________ number gives the n value of the highest principal energy level containing electrons. for main group elements only, the _________ number is always equal to the number of valence electrons.
period; group
why do atomic radii generally increase down a group on the periodic table?
the outer electrons are increasingly farther away from the nucleus and shielded more effectively shells of inner electrons
why do period 2 elements differ from the other elements in the same group?
they have unusually small radii
which of the following options correctly describe the properties and reactivity of Group 3A elements? -Al reacts with acid to liberate hydrogen gas -the metallic elements form ionic compounds only -B is a metalloid -Al is a metal -both boron and aluminum are reactive toward oxygen gas and water
-Al reacts with acid to liberate hydrogen gas -B is a metalloid -Al is a metal
why does ionization energy generally increase from left to right across a period?
-effective nuclear charge increases and the outermost electron becomes harder to remove
which of the following factors affect the type of oxide formed by an alkali metal? -the concentration of O available during the reaction -the stability of the oxide in the solid state -the ability of the metal to form a covalent bond to O -the stability of the oxide in aqueous solution -the attraction between the metal cation (M+) and the oxygen anion present
-the stability of the oxide in the solid state -the attraction between the metal cation (M+) and the oxygen anion present
what does it mean if two species are isoelectronic?
-they have the same electron configuration -they have the same number of electrons
which types of electrons are best at shielding a 3p electron?
2p - electrons in inner shell energy levels are best at shielding outer electrons
which alkaline earth metals form compounds that are covalent rather than ionic?
Beryllium Magnesium -(elements toward the top of any group have the lowest metallic character; among the alkali metals, that means that beryllium and magnesium can form covalent compounds)
