Highlander Help

CHAPTER 8 BASIC HOMEWORK

Resources:

Have you found videos, websites, or explanations that helped you understand this chapter? Let us know and we'll add them to "Resources" part of this page for other students to use.


Use CTRL + F to find all the question, Order may vary

 

Question 1

What is the ground-state electron configuration for Cr? Use abbreviated notation. For example, Ti is [Ar]4s23d2. Write [Ar]4s23d2 or [Ar] 4s2 3d2. 

Help: Ground state exceptions

 

Explanation

Click on picture to enlarge

 

Question 2

What is the ground-state electron configuration for Ni? Use abbreviated notation.

 

Explanation

 

Question 3

What is the ground-state electron configuration for Ag? Use abbreviated notation. Careful, Ag is an exception


 

Explanation

 

Question 4

Which of the following electron configurations is correct for the ground state of Cr?
Help: Hund's rule
Cr is tricky. Additional help given in feedback

Select one:
Correct

 

Explanation

 

Question 5

How many unpaired electrons are in the ground state of Cr?

Help: Electron configurations and magnetism

Select one:
Correct

 

Explanation

  

 

Question 6

Which of the following elements are diamagnetic (all electron spins are paired)?


Select one or more:
Correct
Correct

 

Explanation

All elements that are noble gases are diamagnetic . All elements in group 2A in periodic table are diamagnetic.

 

Question 7

Which of the following elements have 1 unpaired electron and consequently are paramagnetic? (electrons that are not in a pair)

Select one or more:
Correct
Correct
Correct

 

Explanation

 

Question 8

Which of the following elements have 2 unpaired electrons and consequently are paramagnetic?

Select one or more:
Correct
Correct

 

Explanation

 

Question 9

Which of the following elements has 3 unpaired electrons and consequently is paramagnetic?

Select one:
Correct

 

Explanation

 

Question 10

Arrange the following atoms in order from smallest to largest atomic radius: Be, Mg, Ca, and Ba. For Mg and Na, write Mg Na or Mg, Na. Hint, make sure you use the periodic table.

 

Explanation

Summarizing Atomic Radii for Main-Group Elements:

  • As we move down a column in the periodic table, the principal quantum number (n) of the electrons in the outermost principal energy level increases, resulting in larger orbitals and therefore larger atomic radii.
  • As we move to the right across a row in the periodic table, the effective nuclear charge experienced by the electrons in the outermost principal energy level increases, resulting in a stronger attraction between the outermost electrons and the nucleus, and smaller atomic radii.

 

Question 11

Arrange the following atoms in order from smallest to largest atomic radius: Mg, Si, P, and Ar.

 

Explanation

Summarizing Atomic Radii for Main-Group Elements:

  • As we move down a column in the periodic table, the principal quantum number (n) of the electrons in the outermost principal energy level increases, resulting in larger orbitals and therefore larger atomic radii.
  • As we move to the right across a row in the periodic table, the effective nuclear charge experienced by the electrons in the outermost principal energy level increases, resulting in a stronger attraction between the outermost electrons and the nucleus, and smaller atomic radii.

 

Question 12

Arrange the following atoms in order from smallest to largest atomic radius: O, F, Al, and P.

 

Explanation

Summarizing Atomic Radii for Main-Group Elements:

  • As we move down a column in the periodic table, the principal quantum number (n) of the electrons in the outermost principal energy level increases, resulting in larger orbitals and therefore larger atomic radii.
  • As we move to the right across a row in the periodic table, the effective nuclear charge experienced by the electrons in the outermost principal energy level increases, resulting in a stronger attraction between the outermost electrons and the nucleus, and smaller atomic radii.

 

Question 13

Arrange the following atoms in order from smallest to largest ionization energy: Be, Mg, Ca, and Ba. Hint, make sure you use the periodic table.

Help: Ionization energy trends

 

Explanation

Ionization Energy - required energy to remove an electron from orbital

  • First ionization energy  decreases as we move down a column (or family) in the periodic table because electrons in the outermost principal level are increasingly farther away from the positively charged nucleus and are therefore held less tightly.
  • First ionization energy increases as we move to the right across a row (or period) in the periodic table because electrons in the outermost principal energy level generally experience a greater effective nuclear charge

 

Question 14

Arrange the following atoms in order from smallest to largest ionization energy: O, Ne, Mg, and S.

 

Explanation

Ionization Energy - required energy to remove an electron from orbital

  • First ionization energy decreases as we move down a column (or family) in the periodic table because electrons in the outermost principal level are increasingly farther away from the positively charged nucleus and are therefore held less tightly.
  • First ionization energy increases as we move to the right across a row (or period) in the periodic table because electrons in the outermost principal energy level generally experience a greater effective nuclear charge

 

Question 15

Arrange the following atoms in order from smallest to largest ionization energy: F, Cl, Br, and Ga

 

Explanation

  • First ionization energy decreases as we move down a column (or family) in the periodic table because electrons in the outermost principal level are increasingly farther away from the positively charged nucleus and are therefore held less tightly.
  • First ionization energy increases as we move to the right across a row (or period) in the periodic table because electrons in the outermost principal energy level generally experience a greater effective nuclear charge

 

Question 16

Arrange the following atoms and ions in order from smallest to largest radius: Li, Li+, and Be. Hint, make sure you use the periodic table.



 

Explanation

 protons electrons
Li+3 2strongest attraction to nucleus (smallest)
Be44strong attraction to nucleus (right of Li) (smaller than Li)
Li3 3 weak attraction (to the left of Be) (bigger than Be)

Summarizing Atomic Radii for Main-Group Elements:

  • As we move down a column in the periodic table, the principal quantum number (n) of the electrons in the outermost principal energy level increases, resulting in larger orbitals and therefore larger atomic radii.
  • As we move to the right across a row in the periodic table, the effective nuclear charge experienced by the electrons in the outermost principal energy level increases, resulting in a stronger attraction between the outermost electrons and the nucleus, and smaller atomic radii.

 

Question 17

Arrange the following atoms and ions in order from smallest to largest radius: P3-, Cl-, and Ar. Hint, make sure you use the periodic table. Additional hint, when the number of electrons is the same, the one with the largest nuclear charge (most protons) will hold the electrons best (be the smallest).

 

Explanation

 protons electrons
P3- 15 18 weakest attraction to nucleus (larger radius)
Cl- 17 18 medium attraction to nucleus (medium radius)
Ar 18 18 strongest attraction to nucleus (smallest radius)
 

Question 18

Which of the following elements has the most negative electron affinity, that is, which has the strongest affinity to acquire an additional electron: Al, Si, S, Cl?

Help: Electronegativity and electron affinity trends

 

Explanation

Electron Affinity - the energy change associated with the gaining of an electron

  • Among the group 1A metals, however, electron affinity becomes more positive as we move down a column (adding an electron becomes less exothermic).

  • Electron affinity generally becomes more negative (adding an electron becomes more exothermic) as we move to the right across a period (row) in the periodic table

 

Question 19

Which of the following elements has the largest electronegativity: Al, Si, S, Cl?

 

Explanation

Electronegativy- the ability of an atom to attract an electron in a chemical bond

• Electronegativity increases across a period in the periodic table.
• Electronegativity decreases down a column in the periodic table.


In general, electronegativity is inversely related to atomic size—the larger the atom, the less ability it has to attract electrons to itself in a chemical bond

 

Question 20

Which of the following compounds is the most ionic: LiCl, NaCl, CsCl, and AlCl3? For H2O, write H2O.
 

Explanation

The greater the electronegativity difference the more ionic


  

  


LiCl = 1.0 - 3.0 = 2.0 (polar covalent)

NaCl = 0.9 - 3.0 = 2.1 (ionic)

CsCl = 0.7- 3.0 = 2.3  (ionic)

AlCl3 =  1.5-3.0 = 1.5  (polar covalent)





 

Question 21

Which of the following compounds is the most ionic: NaCl, BaF2, Li2S, CH4, and NH3?

 

Explanation

NaCl = 0.9 - 3.0 = 2.1 (ionic)

BaF2 = 1.5 - 4.0 = 2.5 (ionic)

Li2 S = 1.0 - 2.5 = 1.5  (polar covalent)

CH4 = 2.5 -2.1 = .4 (covalent)