Chapter 9 Basic Homework

1. Match the following with the kind of bond which is makes

Answer :     FI -- Polar Covalent because one of the atom is negative and other one is Positive

                    CsI -- Ionic Bonding  -- One or more electron transferred between atoms
                    H2 -- Purely Covalent -- 2 electron equally shared between atoms.

2. What is the difference in electronegativity between the atom in HI?
Answer:    0.4 -- refer the table above I(2.5) - H(2.1) = 0.4

3. Which of the atoms in HI has a partial positive charge? Namely, when HI is placed in the electric field between two charged plates, which atom would point towards the negative plate? Write either H or I
Answer: H -- H+ and I- 

4.  How many valence electron does Boron have? 

Answer:  3 

How:  As you can see 13 above B means 3 valence electron, 14 above Carbon means 4 valence electron and so forth 5 for nitrogen, 6 for Oxygen, & for Fluorine, 8 for Neon.

5. How many valence electron does magnesium have ?

Answer: 2 -- same logic as above.

6. How many valence electron does bromine have ?

Answer:  7

7. How many valence electron does argon have ?

Answer: 8

8. Which letter (a, b, c, d, e, f, g, or h) shows correct lewis structure for O?

Answer: F, because Oxygen have 6 valence electron.

9. Which letter shows correct lewis structure for S?

Answer:  Same as Oxygen it falls under same column. F

10. Which letter shows correct lewis structure for Kr?

Answer: H

11. Which letter shows correct lewis structure for Ga?

Answer: C

12. Which of the following statement about Lewis Structure is FALSE?

Answer: 

a. The noble gases have 8 valence electrons, except He which has 2.

b. For the noble gases these are placed in 4 pairs. Each pair represents an electron orbital with two electrons.

c. The octet rule states that elements like to have 8 valence eletrons in order to have the stable noble gas electron configuration. Note, however, that H likes to have 2 valence electrons to be like He.

d. To have the stable noble gas electron configuration, N generally makes 3 bonds.

e. To have the stable noble gas electron configuration, C generally makes 4 bonds.

f. To have the stable noble gas electron configuration, C generally makes 5 bonds. 

13.  Write the Lewis Structure H₂O for and check those statement which are correct.

a. O is the central atom. 

b. One of the H is the central atom.

c. There are 6 valence electrons.

d. There are 8 valence electrons. 

e. There are 10 valence electrons.

f. O has 0 lone pair of electrons.

g. O has 1 lone pair of electrons.

h. O has 2 lone pairs of electrons.  

Chemistry Chapter 8 basic Home work

• 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. 

      Answer:  [Ar] 4s1 3d5   Make sure you leave space in between as you see

      

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

     Answer: [Ar] 4s2 3d8

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

    Answer:  [kr] 5s1 4d10

• Which of the following electron configurations is correct for the ground state of Cr? 

     Answer: 

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

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

• Which of the following elements have 1 unpaired electron and consequently are paramagnetic?

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

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

• 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. 

Answer: Be, Mg, Ca, Ba

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

Answer: Ar, P, Si, Mg

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

Answer: F, O, P, Al

• 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.

Answer: Ba, Ca, Mg, Be

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

Answer: Mg, S, O, Ne

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

Answer: Ga, Br, Cl, F

• 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. 

Answer: Li+, Be, Li

• Arrange the following atoms and ions in order from smallest to largest radius: P^3-, 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).

Answer: Ar, Cl-, P3-

• 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? 

Answer: Cl

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

Answer:Cl

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

Answer: CsCl

• 
  

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

Answer: BaF2

References you needed to do other problems 

Electronegativity

Atomic radius trend

Electron Affinity Trend