Chem100/11 Assignment 6 2012/2013

Due to March 25

Electronic Structure of Atoms. Periodic properties of the Elements (Chapters 6 and 7)

1. {5}

(a) What is the wave length (in nm) of radiation that has frequency of 6.1 x 10¹⁴ s^-1 ? (c= 3.00 x10⁸ m/s) (hint: sample exercise 6.2)

(b) what part of the electromagnetic spectrum this radiation belongs to? (for example, X rays, Infrared, etc. Hint: chapter 6.1 in the text)

2. {10}

a) there are _____ orbitals in the first electron shell

b) there are _____ orbitals in the second electron shell

c) there are maximum _____ electrons in the p-subshell

d) there are maximum _____ electrons in the f-subshell

e) the principle quantum number for the first d subshell is _____

f) Each d-subshell can accommodate maximum ______ electrons

g) A p_z orbital is degenerate with _____ orbitals in a many-electron atom

h) the 2p subshell in a ground state of atomic nitrogen contains _____ electrons

i) there is/are ______ unpaired electrons in oxygen atom

j) [Ar] 3d²4s² is the electron configuration of a(n)__ ___ atom

3. {5}

Which of the following sets of four quantum numbers (n, l, m_l, m_s) are valid and which are not?

a) 2, 1, 0, 1

b) 2, 1, 0, -1/3

c) 3, 2, 0, ½

d) 2, 1, 0, +1/2

e) 2, 1, 2, -1/2

4. {10} For each atom/ion, write down the number of valence electrons and unpaired electrons in the ground state

a) (2) hydrogen

b) (2) carbon

c) (2) nitrogen

d) (2) fluorine

e) (2) Fe²⁺

5. {5} Using the periodic table, write down the condensed ground state electronic configurations for Cl, Co⁺, Na, Br^- , and C.

6. {5} Write down the condensed ground state electronic configurations for V and Cr and Ni and Cu. Briefly explain the singularities.

7. {5} write down the following elements in order of increasing first ionization energies (IE₁). Briefly explain the singularities in the trend (hint: section 7.9) :

Cl, P, S, Al, Si, Na, Mg

8. {10} An element, X, with the highest principal quantum number n = 4, has the following ionization energies, IE:

IE1= 1000 kJ/mol; IE2= 2252kJ/mol; IE3= 3357 kJ/mol; ; IE4=4556 kJ/mol; IE5=7004 kJ/mol; IE6=8496; IE7=27107 kJ/mol.

a) {4} Identify the element

b) {3} Write down balanced reaction between the element and molecular oxygen. Show physical states.

c) {3} Would you expect the product of the chemical reaction of the element with O₂ to be a basic, or an acidic oxide? Write down chemical equation for the reaction between the oxide and water.

9. {10} Write down empirical formula for the ionic compound that best fit the following descriptions:

(a) the alkali cation with the smallest radius and an anion with the smallest radius

(b) The alkaline earth metal with the highest ionization energy that combines in a 2:1 ratio with the element from Period 3.

(c) The largest element from period 5 combined with the Group 16 element with the most negative electron affinity.

(d) The compound formed from the elements of Period 3 that have the largest radius and most negative electron affinity.

10. {10} Write balanced equations for the following reactions:

(a) potassium oxide with water

(b) diphosphorus pentoxide with water

(c) sulfur trioxide with solution of sodium hydroxide

(d) magnesium with chlorine

(e) Fe (II) oxide with diluted hydrochloric acid

11. {5} Write down the condensed electron configuration for the following ions:

K⁺, Mg²⁺, Cr³⁺, P³⁺, P^3-, N^3-, S^2-, F^-, I⁷⁺, Cu⁺.

12. {10} write down the most common monoatomic ions formed from the following atoms:

Li, Ca, Al, H, O, F, Cl, S, Br, N

13. {5} arrange the following oxides in order of increasing basicity (from the most acidic to the most basic):

SO₃, CaO, Fe₂O₃, CO₂, Na₂O, H₂O

14. {5} Arrange the following atoms in order of increasing radius:

K, Ge, Rb, Br, F

15. {5} Arrange the following atoms in order of increasing (more negative) electron affinities ( chapter 7.5) :

Cl, F, N, O, C, Be, Li, S, H, P