Chapter 5

Question 1

Ionization energy

Answer 1

minimum energy required to remove one electron from an atom in its ground state

Question 2

True or False? It is easier to remove an electron from a cation.

Answer 2

False. It is harder.

Question 3

True or False? The total number of electrons in an atom affects the ionization energy.

Answer 3

True

Question 4

True or False? An electron in a multielectron atom is attracted to the nucleus, but repelled by the other electrons.

Answer 4

True

Question 5

Screening

Answer 5

electron-electron repulsion cancels out some of the nuclear-electron attraction; electrons are primarily screened by inner electrons

Question 6

Pauli Exclusion Principle

Answer 6

each electron has a unique set of four quantum numbers (n, l, ml, ms)

Question 7

Aufbauf Principle

Answer 7

fill in orbitals starting with lowest energy orbital

Question 8

Hund’s rule

Answer 8

most stable configuration is the one with the maximum number of electrons with the same spin

Question 9

Write the electron configuration for Na.

Answer 9

[Ne] 3s1

Question 10

Core electrons vs valence electrons

Answer 10

valence electrons: have highest principle quantum number plus partially filled d and f orbitals
core electrons: all the rest

Question 11

Write the electron configuration for Ge2+.

Answer 11

[Ar]4s2 3d10

Question 12

Write the electron configuration for Cu-

Answer 12

[Ar] 4s2 3d10

Question 13

What happens to the atomic radius when electrons are added to an atom?

Answer 13

the atom gets bigger

Question 14

Put the following in order from biggest to smallest atomic radius.
Na+ , Ne, O2-, F-, Mg2+

Answer 14

O2-, F-, Ne, Na+, Mg2+

Question 15

Lattice energy

Answer 15

the energy released when an ionic solid decomposes into gaseous ions ; a measure of the attractive force holding those ions together

Question 16

What happens to lattice energy when the charge on ions increases?

Answer 16

increases

Question 17

What happens to lattice energy when size of atoms increases?

Answer 17

decreases

Question 18

Paramagnetic vs diamagnetic

Answer 18

paramagnetic: unpaired spins; attracted to magnetic field
diamagnetic: paired spins; repelled by magnetic field

Question 19

Give the chemical symbol for the element with the following ground-state electron configuration.
[Ne] 3s2 3p3

Answer 19

P

Question 20

Nonmetals gain electrons under certain conditions to attain a noble-gas electron configuration. How many electrons must be gained by the element O?

Answer 20

2 electrons

Question 21

Which noble gas electron configuration is attained in the element O gaining two electrons?

Answer 21

neon

Question 22

The effective nuclear charge, Zeff, for a valence electron can be approximated using the core charge of the atom, that is, the total charge of the nucleus and the inner electrons. determine the core charge for an atom of Cl.

Answer 22

nuclear charge= +17
core negative charge = -10

total electrons - valence electrons = core charge
(+17) + (-10) = +7

Question 23

Give the complete electron configuration for Br.

Answer 23

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5

Question 24

Identify the number of core electrons for the following atoms:

a) Ar
b) Be
c) F

Answer 24

total electrons - valence electrons = core charge

a) 18-8=10
b) 4-2=2
c) 9-7=2

Question 25

Most transition metal cations are paramagnetic, but there are some exceptions. Identify which of these first-series transition metals could form diamagnetic cations with charges of +3 or less, and which are paramagnetic. Mn, Ni, Cu, Ti, Sc, Cr, Co, Fe, V, Zn

Answer 25

diamagnetic: Sc, Cu, Zn paramagnetic: Ti, V, Cr, Mn, Fe, Co, Ni

Question 26

For each atom or ion below, determine the number of unpaired electrons. a) Ni2+ b) V2+ c) Fe d) As

Answer 26

``` a) [Ar] 4s2 3d8 2 electrons b) [Ar] 4s2 3d3 3 electrons c) [Ar] 4s2 3d6 4 electrons d) [Ar] 4s2 3d10 4p3 3 electrons ```

Question 27

What is the electron configuration for Ga?

Answer 27

[Ar] 4s2 3d10 4s1

Question 28

Give the full electron configuration for Al.

Answer 28

1s2 2s2 2p6 3s2 3p1

Question 29

Arrange these elements according to atomic radius from largest to smallest. Cl, Al, Ar, Na, Mg, Si, P, S

Answer 29

Na, Mg, Al, Si, P, S, Cl, Ar

Question 30

Rank the following ions from largest to smallest ionic radius. Rb+, Y3+, Se2-, Mo6+, Br-

Answer 30

Se2-, Br-, Rb+, Y3+, Mo6+

Question 31

Describe the charge distribution (electronegativity) in OF2.

Answer 31

O is delta + | F is delta -

Question 32

Rank these elements according to first ionization energy from highest to lowest. Sn, C, Ge, Si

Answer 32

C, Si, Ge, Sn

Question 33

Based on ion sizes, rank these compounds according to their expected lattice energy, from greatest to least. NaCl, NaBr, NaF, NaI

Answer 33

NaF, NaCl, NaBr, NaI

Question 34

How does the electron affinity of the single charged cation Na+ relate to the ionization energy of the neutral atom?

Answer 34

The electron affinity of Na+ is the same magnitude as the ionization energy of Na, but has the opposite sign.

Question 35

Rank the following ions by their ionic radius from largest to smallest. P3-, Ca2+, Cl-, K+, S2-

Answer 35

P3-, S2-, Cl-, K+, Ca2+

Question 36

Rank the following by the most to least electronegative. | Al, O, C, Rb, Na

Answer 36

O, C, Al, Na, Rb

Question 37

What is the ground state configuration for I-?

Answer 37

[Kr] 5s2 4d10 5p6

Question 38

Which one of the following is expected to be repelled by a magnetic field? a) F b) Ca2+ c) N d) Al e) Mg+

Answer 38

b) Ca2+

Question 39

Arrange the following in order of decreasing atomic radius: | Cl- , K+, Cl, Br-

Answer 39

Br-, Cl-, Cl, K+

Question 40

List B, Ca, and Rb from easiest to most difficult to ionize.

Answer 40

Rb, Ca, B

Question 41

Which of the following form an isoelectronic group? a) Ge, As, Se b) I-, Xe, Cs+ c) Br, Kr, Se2- d) O, S, Se e) N3-, P3-, As3-

Answer 41

b) I-, Xe, Cs+

Question 42

The lattice energies for NaF, NaBr, NaI and Na2O are 910, 732, 682, and 2481. Which of the following is most likely the lattice energy for NaCl? a) 595 b) 769 c) 940 d) 1051 e) 1700

Answer 42

b) 769

Question 43

Which one of the following species has the most unpaired electrons? a) S b) Si c) Al d) S2- e) F

Answer 43

a) S | b) Si

Question 44

Provide the ground state electron configuration for Br+ and write 4 valid sets of quantum numbers for only the valence p electrons.

Answer 44

[Ar] 4s2 3d10 4p4 n=4, l=1, ml= -1, ms= 1/2 n=4, l=1, ml= -1, ms= -1/2 n=4, l=1, ml=0, ms= 1/2 n=4, l=1, ml=+1, ms= 1/2