CHEM 108 - Homework 4
[Ar]4s²3d⁵
what is the electron configuration for Mn
isoelectronic
__ species are elements/ions with the same electron configuration (same number of electrons)
1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s
according to the Aufbau principle, the order in which atomic orbitals are filled are:
Fe²⁺ and Mn³⁺ isoelectronic species are elements/ions with the same electron configuration (same number of electrons)
all of the following pairs of ions are isoelectronic except which one? a) Al³⁺ and N³⁻ b) Fe²⁺ and Co³⁺ c) Fe²⁺ and Mn³⁺ d) K⁺ and Ca²⁺
1s²2s²2p⁶3s²3p⁶ has three additional electrons (due to its charge of 3-), so three electrons must be added to the atom
electron configuration of P³⁻
they were believed to be 'too noble' to react with other elements
group 18 elements were called the noble gases originally because
gaining electrons will fill their octet faster than losing them
halogens tend to form anions because
2 Be has 4 e- & an electron configuration of 1s²2s²1s²2s² the e- in the 1st shell are in the core & the electrons in the outer shell are valence electrons
how many core electrons does an atom of beryllium (Be) contain
2 1s²2s²2p⁵
how many electrons are in the n = 1 shell in a neutral fluorine atom
8 it has an electron configuration of 1s²2s²2p⁶3s²; eight electrons in the 2s and 2p levels correspond to a full second energy shell
how many electrons are in the n = 2 shell of a magnesium atom
5 electron configuration of 1s²2s²2p³
how many electrons are in the n = 2 shell of a nitrogen atom?
8 Ca has 8 electrons in the n = 3 shell; it has an electron configuration of 1s²2s²2p⁶3s²3p⁶4s²; Ca has full 3s & 3p subshells, which can hold 2 & 6 electrons
how many electrons are in the n = 3 shell in a neutral calcium atom?
7
how many valence electrons are in a neutral atom of chlorine?
core, valence electrons
the electrons in the 1st shell are in the __ & the electrons in the outer shell are __
1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁴
the ground state electron configuration of a Se atom is
1s²2s²2p⁶3s²3p⁶ K⁺ ion has one fewer electron (due to its positive charge), so the highest-energy electron must be removed from K to create K⁺
what is the electron configuration of K⁺
1s²2s²2p⁶3s²3p⁶4s¹
what is the electron configuration of a neutral K atom
Kr the noble gas core for a given element is the last noble gas filled in the periodic table prior to the given element; here, the last noble gas prior to Sb is Kr, so that is its noble gas core
what is the noble gas core in the electron configuration for Sb?
Rn the noble gas core for a given element is the last noble gas filled in the periodic table prior to the given element; here, the last noble gas prior to U is Rn, so that is its noble gas core
what is the noble gas core in the electron configuration for U?
Cr exception due to the formation of a half-filled 3d shell with a 3d⁵ configuration; having two half-filled orbitals is more stable than having one partially filled (but not exactly half-filled) & one completely filled
which element has the electron configuration 1s²2s²2p⁶3s²3p⁶4s¹3d⁵ a) V b) Cr c) Mo d) Mn
Br the 5 in 4p⁵ indicates that it is the fifth element in this row, so the element must be Br
which element has the ground state electron configuration [Ar]4s²3d¹⁰4p⁵
W the 4 in 5d⁴ indicates that it is the fourth element in this row, so the element must be W
which element has the ground state electron configuration [Xe]6s²4f¹⁴5d⁴
O²⁻ has 10 electrons with an electron configuration the same as the noble gas Neon, Ne of 1s²2s²2p⁶
which following ions share an electron configuration with a noble gas? a) N⁻ b) H+ c) F³+ d) O²⁻
metals
which groups of elements tend to form cations
N
which of the following atom(s) below has/have five valence electrons? a) C b) N c) O d) F
S [Ne]3s³3p⁴ It is not possible to have 3 electrons in the 3s orbital; this would be a violation of the Pauli exclusion principle
which of the following electron configurations is incorrect a) S [Ne]3s³3p⁴ b) Sn [Kr]5s²4d¹⁰5p² c) Rb [Kr]5s¹ d) V [Ar]4s²3d³
silicon
which of the following has four valence electrons? a) silicon b) neon c) beryllium d) boron
V²⁺
which of the following has the electron configuration 1s²2s²2p⁶3s²3p⁶3d³ a) V³⁺ b) Mn³⁺ c) Cr²⁺ d) V²⁺
helium
which of the following has two valence electrons? a) potassium b) helium c) oxygen d) argon
[Xe]6s²
which of the following is the electron configuration for Ba? a) [Xe]6s² b) [Rn]6s² c) [Xe]7s² d) [Rn]7s²
1s²2s²2p⁶3s²3p⁶4s²3d⁶
which of the following is the electron configuration of a neutral Fe atom?
Al³⁺ and O²⁻ both have electron configuration of Ne (1s²2s²2p⁶)
which of the following pairs of ions represent isoelectronic species? a) Na⁺ and N²⁻ b) Al³⁺ and O²⁻ c) K⁺ and Na⁺ d) Cl⁻ and F⁻
1s²2s²2p⁶3s²3p⁵ has additional electron due to its charge of 1-, so an electron must be added to the atom
which of the following represents the electron configuration of S⁻ A) 1s²2s²2p⁶3s²3p⁶ B) 1s²2s²2p⁶3s²3p⁵ C) 1s²2s²2p⁶3s²3p⁴ D) 1s²2s²2p⁶3s²3p³
4p⁷ there are three 4p orbitals, each of which can hold two electrons meaning that a p orbital can only hold 6 electrons
which of the orbital electron configurations is not possible? a) 2s¹ b) 3d¹⁰ c) 4p⁷ d) 4f⁷
0 carbon has an electron configuration of 1s²2s²2p²
wow many electrons are in the n = 3 shell of a carbon atom
1s²2s²
write the complete ground-state electron configuration of Be
1s²2s²2p⁶3s²3p¹
write the complete ground-state electron configuration of aluminum
