Q: Using Slater's rules, calculate the effective nuclear charge ($Z_{\text{eff}}$) for a valence electron in phosphorus ($Z=15$) with 5 valence and 10 core electrons.

$Z_{\text{eff}} = 15 - [5(0.35) + 10(0.85)] = 15 - 9.0 = 6.0$

Q: Which of the following best describes the process of ionic bonding in sodium chloride?

Na atoms transfer electrons to Cl atoms, forming $Na^+$ and $Cl^-$ ions that are held together by electrostatic attraction.

Q: Which of the following best explains why anions are larger than their parent atoms?

Anions have more electrons, increasing electron-electron repulsion and expanding the electron cloud.

Question 1

Which of the following statements best explains why elements in the same group of the periodic table have similar chemical properties?

Accepted Answer

They have the same number of valence electrons.

Question 2

What is the electron configuration of a neutral sulfur atom, and how many valence electrons does it have?

Accepted Answer

$1s^22s^22p^63s^23p^4$, 6 valence electrons

Question 3

Which element is in period 3, group 2A, and how many valence electrons does it have?

Accepted Answer

Magnesium, 2 valence electrons

Question 4

Which of the following best describes the trend in atomic radius across a period from left to right?

Accepted Answer

Atomic radius decreases due to increasing effective nuclear charge.

Question 5

Using Slater's rules, calculate the effective nuclear charge ($Z_{	ext{eff}}$) for a valence electron in phosphorus ($Z=15$) with 5 valence and 10 core electrons.

Accepted Answer

$Z_{	ext{eff}} = 15 - [5(0.35) + 10(0.85)] = 15 - 9.0 = 6.0$

Question 6

Which of the following ions is largest in size: $Cl^-$, $K^+$, or $Ca^{2+}$? All are isoelectronic.

Accepted Answer

$Cl^-$

Question 7

Which of the following best explains why cations are smaller than their parent atoms?

Accepted Answer

Cations have more protons than electrons, increasing attraction to the nucleus.

Question 8

Which element has the highest first ionization energy among the following: K, Ga, Se?

Accepted Answer

Se

Question 9

Why is the second ionization energy ($IE_2$) of sodium much higher than the first ionization energy ($IE_1$)?

Accepted Answer

Removing the second electron disrupts a stable noble gas configuration.

Question 10

Which group of elements has the most negative electron affinities, releasing the most energy when forming anions?

Accepted Answer

Group 17 (halogens)

Question 11

Which of the following equations represents the lattice energy for the formation of $CaCl_2$?

Accepted Answer

$Ca^{2+}(g) + 2Cl^-(g) \rightarrow CaCl_2(s)$

Question 12

Which factor will increase the magnitude (make more negative) of the lattice energy of an ionic compound?

Accepted Answer

Increasing the charge of the ions

Question 13

Arrange the following compounds in order of increasing (more negative) lattice energy: $CsF$, $NaF$, $MgCl_2$, $ScN$.

Accepted Answer

$CsF < NaF < MgCl_2 < ScN$

Question 14

Which of the following best describes the process of ionic bonding in sodium chloride?

Accepted Answer

Na atoms transfer electrons to Cl atoms, forming $Na^+$ and $Cl^-$ ions that are held together by electrostatic attraction.

Question 15

Which of the following is the correct formula unit for the ionic compound formed between magnesium and fluorine?

Accepted Answer

$MgF_2$

Question 16

Which of the following best explains why anions are larger than their parent atoms?

Accepted Answer

Anions have more electrons, increasing electron-electron repulsion and expanding the electron cloud.

Question 17

Which of the following best describes the trend in electron affinity across a period?

Accepted Answer

Electron affinity becomes more negative from left to right.

Question 18

Which of the following is the correct expression for the potential energy ($E$) between two ions of charges $q_1$ and $q_2$ separated by distance $r$?

Accepted Answer

$E = k \frac{q_1 q_2}{r}$

Periodicity and Ionic Bonding: Chapter 9 Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards