Section 7 iclicker questions

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Reading assignment: 7.1-7.5

As you read ask yourself:

What is meant by the expression “effective nuclear charge”?

How can you use this concept to explain the trends in atomic radius in the periodic table?

How can you use effective nuclear charge and electron configuration to predict what happens to the radius when ions are formed?

Why is the second ionization energy always greater than the first ionization energy?

What types of elements have the highest ionization energies and what types have the lowest ionization energies?

Why can electron affinity values be both positive and negative?

Summary:

easy to form negative ions

easy to form positive ions

smallest atoms

largest atoms

Section 7 iclicker questions

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A. The order of atomic masses on the periodic table is in no way related to atomic numbers.

B. The atomic number depends on the number of protons in the nucleus, while the atomic weight depends on the number of both protons and neutrons in the nucleus.

C. Atomic masses are a function of group numbers on the periodic table and do not increase linearly with atomic number.

D. For certain midperiodic table elements, the effective mass of each proton in the nucleus varies.

A. The order of atomic masses on the periodic table is in no way related to atomic numbers.

B. The atomic number depends on the number of protons in the nucleus, while the atomic weight depends on the number of both protons and neutrons in the nucleus.

C. Atomic masses are a function of group numbers on the periodic table and do not increase linearly with atomic number.

D. For certain midperiodic table elements, the effective mass of each proton in the nucleus varies.

Section 7 iclicker questions

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A) 2s orbital B) 2p orbital C) 3s orbital D) 3p orbital E) 3d orbital

In an germanium atom, which electron will experience the greatest effective nuclear charge (Zeff)? An electron in a…

• 2s orbital • 2p orbital • 3s orbital • 3p orbital • 3d orbital

In an germanium atom, which electron will experience the greatest effective nuclear charge (Zeff)? An electron in a…

Ge is 1s22s22p63s23p64s23d104p2 or [Ar]4s23d104p2

Z is 32 and S increases as we move to orbitals that are further out.Zeff = Z-S, and therefore 2s has the greatest Zeff

Section 7 iclicker questions

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A) 2s orbital B) 2p orbital C) 3s orbital D) 3d orbital

In an nickel atom, which electron will experience the greatest effective nuclear charge (Zeff)? An electron in a…

• 2s orbital • 2p orbital • 3s orbital • 3d orbital

In an nickel atom, which electron will experience the greatest effective nuclear charge (Zeff)? An electron in a…

Ni is 1s22s22p63s23p64s23d8 or [Ar]3d84s2

Z is 28 and S increases as we move to orbitals that are further out.Zeff = Z-S, and therefore 2s has the greatest Zeff

Section 7 iclicker questions

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A) The atomic number (number of protons)B) The atomic number and the number of electrons in the core shells.C) The atomic number, the number of electrons in the core shells, the number of electrons in the valence shell.D) The atomic number, the number of electrons in the core shells, the number of electrons in the valence shell and the distance from the nucleus.

What determines the effective nuclear charge on a valence electron?

C) The atomic number (Z=attraction to nucleus), the number of electrons in the core shells (S=effective shielding, each electron shields for almost 1) , the number of electrons in the valence shell (S=contributes, each electron shields for less than 1 (0.35)).

D) The atomic number, the number of electrons in the core shells, the number of electrons in the valence shell and the distance from the nucleus. This gives the total attractive force of the electron to the nucleus.

What determines the effective nuclear charge (Zeff) on a valence electron?

Section 7 iclicker questions

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A) 1s22s22p63s23p64s23d104p2 or [Ar]4s24p2

B) 1s22s22p4 [He] 2s22p4

C) 1s22s22p63s23p4 or [Ar] 3s23p4

D) 1s22s22p63s23p6

E) 1s22s22p63s23p4 or [Ne] 3s23p4

What is the electron configuration of S? When done identify and count the core electron and valence electrons (next question).

A) 1s22s22p6 are core (10 total) 3s23p4 are valenceB) 1s22s22p63s2 (12 total) are core 3p4 are valenceC) 1s22s22p6 3s23p3 (15 total) are core 3s23p1 is valence

What are the core and valence electrons of S( 1s22s22p63s23p4 or [Ne] 3s23p4)

Section 7 iclicker questions

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A) Exactly 10B) Less than 10C) More than 10D) Can’t tell without Slater’s rules calculations

What is the S (shielding value) used to calculate Zeffof the valence electrons in sodium(1s22s22p6 are core (10 total) 3s1 are valence)

A) Exactly 10B) Less than 10C) More than 10D) Can’t tell without Slater’s rules calculations

What is the S (shielding value) used to calculate Zeffof the valence electrons in sodium(1s22s22p6 are core (10 total) 3s1 are valence)

Section 7 iclicker questions

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A) Exactly 10B) Less than 10C) More than 10D) Can’t tell without Slater’s rules calculations

What is the S (shielding value) used to calculate Zeffof the valence electrons in sulphur(1s22s22p6 are core (10 total) 3s23p4 are valence)

A) Exactly 10B) Less than 10C) More than 10D) Can’t tell without Slater’s rules calculations

What is the S (shielding value) used to calculate Zeffof the valence electrons in sulphur(1s22s22p6 are core (10 total) 3s23p4 are valence)

Section 7 iclicker questions

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Which would you expect to experience a greater effective nuclear charge, a 2p electron of a Ne atom or a 3s electron of a Na atom?

A) The 2p electron of a Ne atom.B) This cannot be determined without knowing the charge of the atom.C) Both the 2s electron and 2p electron experience the same effective nuclear charge.D) The 3s electron of a Na atom.

Which would you expect to experience a greater effective nuclear charge, a 2p electron of a Ne atom or a 3s electron of a Na atom?

D) The 3s electron of a Na atom.Z increases by one as we move from Ne to Na and S increases by slightly less than one (as shielding is not perfect), therefore Zeff is greater.Zeff=Z-S

Section 7 iclicker questions

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Which of the following is expected to be the correct order of atomic radii from smallest to largest?A) H < C < F

B) Mg < Ar < Al

C) S < Si < Na

D) Ne < B < H

Which of the following is expected to be the correct order of atomic radii from smallest to largest?A) H < C < F

B) Mg < Ar < Al

C) S < Si < Na

D) Ne < B < H

Section 7 iclicker questions

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F, Ne, and Na+ are isoelectronic. Which of the following gives the correct ordering of their ionic size (from smallest to largest)? I

A) F < Ne < Na+

B) Ne < F < Na+

C) Na+ < Ne < F

F, Ne, and Na+ are isoelectronic. Which of the following gives the correct ordering of their ionic size (from smallest to largest)?

A) F < Ne < Na+

B) Ne < F < Na+

C) Na+ < Ne < F

Section 7 iclicker questions

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A. I1 for the boron atom is equal to I2 for the carbon atom.B. I2 for the carbon atom is greater.C. I1 for the boron atom is greater.

A. I1 for the boron atom is equal to I2 for the carbon atom.B. I2 for the carbon atom is greater.C. I1 for the boron atom is greater.

I2 (carbon) > is I1 (carbon) and I1 (carbon) > I1 (boron), therefore I2for the carbon atom is greater..

Section 7 iclicker questions

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Based on periodic trends, which of the following elements is expected to have the largest first ionization energy?

A. Li

B. Be

C. B

D. N

Based on periodic trends, which of the following elements is expected to have the largest first ionization energy?

A. Li

B. Be

C. B

D. N

Section 7 iclicker questions

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Taking into account specific orbitals, which of the following elements is expected to have the largest first ionization energy?

A. Li

B. Be

C. B

D. NE. O

Taking into account specific orbitals, which of the following elements is expected to have the largest first ionization energy?

A. Li

B. Be

C. B

D. NE. O

Section 7 iclicker questions

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Suppose you were asked for a value of the first ionization energy of the Cl-(g) ion. What is the relationship between this quantity and the electron affinity of Cl(g)?

• Both are endothermic and the EA for Cl is significantly more endothermic than I1 for Cl.

• Both are exothermic and the I1 for Cl– is significantly more exothermic than EA for Cl.

• They are similar in magnitude and opposite in sign. • They are similar in magnitude and have the same

sign.

Suppose you were asked for a value of the first ionization energy of the Cl-(g) ion. What is the relationship between this quantity and the electron affinity of Cl(g)?

• Both are endothermic and the EA for Cl is significantly more endothermic than I1 for Cl.

• Both are exothermic and the I1 for Cl– is significantly more exothermic than EA for Cl.

• They are similar in magnitude and opposite in sign. • They are similar in magnitude and have the same

sign.

Section 7 iclicker questions

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Based on periodic trends, which of the following elements is expected to have the largest (i.e., most negative) electron affinity?

A. K

B. Na

C. Si

D. S

Based on periodic trends, which of the following elements is expected to have the largest (i.e., most negative) electron affinity?

A. K

B. Na

C. Si

D. S

Section 7 iclicker questions

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A. the uncertainty principleB. the Pauli exclusion principleC. Hund’s ruleD. the photoelectric effect

Using the periodic table only, which of the following has the lowest Electron affinity?

A) NB) SiC) PD) ClE) O

Section 7 iclicker questions

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Using the periodic table only, which of the following has the lowest Electron affinity?

A) NB) SiC) PD) ClE) O

Four atoms and/or ions are sketched below. Which of the following sets of species are compatible with the sketch?

A) Br, Li+, Se, I-

B) Sr, Cl, Cl-, Na+

C) Li+, Br-, Cl-, Mg2+

Section 7 iclicker questions

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Four atoms and/or ions are sketched below. Which of the following sets of species are compatible with the sketch?

A) Br, Li+, Se, I-

B) Sr, Cl, Cl-, Na+

C) Li+, Br-, Cl-, Mg2+