Answer to Question #163007 in General Chemistry for John

Question

Direction. Answer the following question by following the rules on electronic configuration.

1. Find the electron configurations of the following: (spdf notation and noble gas notation)

a. silicon

b. tin

c. lead

2. Scenario: You are currently studying the element iodine and wish to use its electron 

distributions to aid you in your work.

a. Find the electron configuration of iodine

b. How many unpaired electrons does iodine have?

3. Thought Questions:

a. In your own words describe how to write an electron configuration and why it is an important 

skill in the study of chemistry.

b. Describe the major concepts (Hunds, Pauli...etc.) and explain why each is a key part of the 

"tool kit" when describing electron configurations

c. Why is it possible to abbreviate electron configurations with a noble gas in the noble gas 

notation?

4. Identify the following elements:

a. 1s2

2s2

2p6

3s2

3p6

4s2

3d6

b. 1s2

2s2

2p6

3s2

3p6

4s2

3d10 4p6

5s2

4d7

c. 1s2

2s2

2p6

3s2

3p4

d. 1s2

2s2

2p6

3s2

3p6

4s2

3d10 4p6

5s2

4d10 5p6

6s2

4f14 5d10 6p4

5. Without using a periodic table or any other references, fill in the correct box in the periodic table 

with the letter of each question. (a)The element with electron configuration: 1s2

2s2

2p6

3s2

3p5

; (b)A 

noble gases with f electrons; (c) a fifth-period element whose atoms have three unpaired p electrons; 

(d) First rowtransition metals having one 4s electron.

Answer 1

1. a) Si (silicon) = 1s² 2s² 2p⁶ 3s² 3p²

b) tin (Sn) = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p²

c) lead (Pb) = 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p²

2. a) Iodine (I) = 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁵

b) one unpaired electron

3. a) The symbols used for writing the electron configuration start with the shell number (n) followed by the type of orbital and finally the superscript indicates how many electrons are in the orbital.

The electronic configuration of an atom determines the chemical reactions the atom can participate in, and determines the kinds of molecules that atoms can combine into to form more complicated substances.

b) Hund's rule: every orbital in a subshell is singly occupied with one electron before any one orbital is doubly occupied, and all electrons in singly occupied orbitals have the same spin.

The Pauli Exclusion Principle states that, in an atom or molecule, no two electrons can have the same four electronic quantum numbers. As an orbital can contain a maximum of only two electrons, the two electrons must have opposing spins

c) Noble gas electron configurations are easier to write because they are shorter than full electron configurations. To understand the chemistry of an element, it's most important to know about the electrons in the highest energy levels.

4. a) Iron ( Fe)

b) Rhodium (Rh)

c) Sulphur (S)

d) Polonium ( Po)

5. a) Chlorine ( Cl )

b) Radon (Rn)

c) Antimony (Sb)

d) scandium (Sc)