Chemistry Chapter 3.5

Which of the following atom(s) below has/have five valence electrons? A) C B) N C) O D) F E) All of the above

B) N

What element is theoretically the largest of all on the periodic table? A) Francium (Fr) B) Helium (He) C) Hydrogen (H) D) Lead (Pb) E) Radon (Rn)

A) Francium (Fr)

Which of the following groups of elements tend to form cations? A) Metals B) Metalloids C) Nonmetals D) Noble gases E) Radioactive elements

A) Metals

Which of the following elements would have a very different electron affinity value compared to the others? A) Ne B) Al C) O D) F E) Na

A) Ne

All of these are factors that affect the effective nuclear charge, Zeff, EXCEPT A) mass number B) the type of orbital an electron occupies C) the number of core electrons D) the number of valence electrons E) atomic number

A) mass number

Which of the following types of electrons penetrates most toward the nucleus and therefore has the greatest shielding effect? A) s B) p C) d D) f E) all penetrate equally

A) s

Rank the following atoms in order of decreasing first ionization energies (i.e., highest to lowest): Li, Be, Ba, F. A) Ba > Li > Be > F B) F > Be > Li > Ba C) Li > Be > F > Ba D) F > Be > Ba > Li E) Ba > F > Be > Li

B) F > Be > Li > Ba

Which periodic trend quantifies the amount of energy required to remove an electron from a neutral, gaseous atom? A) Atomic Radius B) Ionization Energy C) Ionic Radius D) Electron Affinity E) Electronegativity

B) Ionization Energy

Identify the list in which the atoms are ordered by increasing Zeff for a valence electron calculated by the simple or approximate method? A) P<S<Si<Cl B) Si<P<S<Cl C) Cl<S<P<Si D) S<Cl<P<Si E) Si<P<Cl<S

B) Si<P<S<Cl

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⁺ E) Zn²⁺ and Cu⁺

C) Fe²⁺ and Mn³⁺

Which of the following radii comparisons is correct? A) N^3- < N B) Ti^4+ > Ti^3+ C) In^3+ < In^+ D) C^4+ > C^4- E) As^3- < As^3+

C) In^3+ < In^+

The atomic radii of zirconium (Zr) and hafnium (Hf) are nearly the same despite the fact that hafnium has 32 more protons and electrons. Which of the following best explains this phenomenon? A) Hafnium has a lower than expected Zeff due to the presence of 4f electrons. B) The extra electrons in hafnium repel one another less than expected and thus the size is smaller than expected. C) The noble gas core of hafnium is not as large as expected and thus the overall size of hafnium is smaller. D) Transition metals experience only small differences in atomic radii unlike main group elements. E) Hafnium contains electrons in the 4f orbitals. These 4f electrons do not effectively shield the higher than might be otherwise expected.

E) Hafnium contains electrons in the 4f orbitals. These 4f electrons do not effectively shield the higher than might be otherwise expected.

The trend towards smaller atomic radii as one moves to the right in a period is _____. A) faulty, as atomic radii in a period are nearly uniform in size. B) because of electron pair repulsion causing the expansion of the orbitals. C) wrong. Atomic radii increase across a period left to right as the larger d and p orbitals are occupied after the s orbital. D) due to the effective nuclear charge decreasing. E) due to the effective nuclear charge increasing.

E) due to the effective nuclear charge increasing.

Which of the following series of isoelectronic ions correctly lists the ions in order of increasing size (i.e., smallest to largest)? A) Ca²⁺ < K⁺ < Cl⁻ < P³⁻ B) K⁺ < Ca²⁺ < P³⁻ < Cl⁻ C) P³⁻ < Cl⁻ < K⁺ < Ca²⁺ D) Cl⁻ < K⁺ < Ca²⁺ < P³⁻ E) K⁺ < Ca²⁺ < Cl⁻ < P³⁻

A) Ca²⁺ < K⁺ < Cl⁻ < P³⁻

In which direction on the periodic table does metallic character increase? A) Down and to the right. B) Down and to the left. C) As you move toward the middle of the table. D) Up and to the right. E) Up and to the left.

B) Down and to the left.

The energy released in the reaction F(g) + e⁻ → F⁻(g) is known as the A) Ionization energy B) Electron affinity C) Enthalpy of ionization D) Electronegativity E) Enthalpy of electronegativity

B) Electron affinity

Elements that are most similar in their properties are found _____ A) in the same period B) in the same group C) have the same electron configurations D) to occur randomly throughout the table E) diametrically opposite each other on the periodic table

B) in the same group

How many core electrons does an atom of beryllium (Be) contain? A) 0 B) 1 C) 2 D) 3 E) 4

C) 2

Considering periodic trends, valence electrons in which of the following atoms experience the greatest effective nuclear charge (Zeff)? A) Cl B) C C) F D) Ne E) B

D) Ne

Rank the following atoms in order of increasing first ionization energies (i.e., lowest to highest): Rb, F, Mg, B, N. A) F < N < B < Mg < Rb B) Rb < Mg < F < N < B C) Mg < Rb < F < N < B D) Rb < Mg < B < N < F E) Rb > B > N > F > Mg

D) Rb < Mg < B < N < F

Effective nuclear charge, Zeff, is defined as A) the number of protons minus the number of valence electrons B) the difference in electronegativities of two bonded atoms or ions C) the number of protons minus the number of electrons D) the true nuclear charge minus the charge that is shielded by electrons E) the number of protons in the nucleus

D) the true nuclear charge minus the charge that is shielded by electrons

Calculate the effective nuclear charge on a valence electron in an oxygen atom.

6

Rank the following atoms in order of increasing size (i.e., smallest to largest): Li, Al, Be, Ba, O. A) Li < Al < Be < Ba < O B) Ba < Al < Li < Be < O C) Li < Be < O < Al < Ba D) O < Be < Li < Al < Ba E) O < Li < Be < Ba < Al

D) O < Be < Li < Al < Ba