# Use the aufbau principle to write the ground state electron configuration of an atom of this element. How many of the electrons in this atom have a principal quantum number of 4?

SCH4U Atomic theory assignment

Problem 1 [ /10]

For the five sets of four quantum numbers below, explain what is wrong with each set for an electron in a one-electron atom.

Make sure to refer back to the limits of each quantum number.

(a)

n = 1,

l = 1,

m l = +1,

m s = +

2

1

(b)

n = 2,

l = 0,

m l = +1,

m s = –

2

1

(c)

n = 3,

l = -1,

m l = 0,

m s = +

2

1

(d)

n = 4,

l = 2,

m l = +3,

m s = 0

(e)

n = 5,

l = +3,

m l = –2,

m s = – 1

Problem 2 [ /5]

Fill in the missing values or names of the following sets of quantum numbers.

(a)

n = 2,

l = ?,

m l = +1; name: 2

p

(b)

n = ?,

l = 0,

m l = ?; name: 4

s

(c)

n = 3,

l = 1,

m l = +1; name: ?

(d)

n = 3,

l = ?,

m l = 0; name: 3

d

Problem 3 [ /5]

Identify the element that matches each of the following descriptions.

(a) The ground state electron configuration of the ion of this element carrying a 4+ charge is [Ar] 4s 2 3

d 3 .

(b) The electron configuration of this element in its first excited state is [Ar] 4

s 1 4

p 1 .3

d 10

(c) The ground state electron configuration of this element is [Xe] 6

s 2 .4

f 1 5

d 1

(d) The ion of this element carrying a charge of 3– has the ground state electron configuration [Xe].

(e) The ground state electron configuration of the ion of this element that has a charge of 5+ is [Kr] 5s 2 4

d 6 .

Problem 4 [ /15]

Use the aufbau principle to write the ground state electron configuration of the following ions.

(a) Ir 4+ (b) Co 3+

(c) In 3+ (d) Bi 3–

(e) Hg +

Problem 5 [ /14]

(a) Explain Pauli Exclusion Principle and Hund’s Rule. (4)

(b) Use orbital diagrams to represent the ground state electron configuration of the ions in problem 4. (10)

Problem 6 [ /6]

The element tungsten has the symbol W, after the name of the ore, wolframite, from which it can be recovered.

(a) Use the aufbau principle to write the ground state electron configuration of an atom of this element. (3)

(b) How many of the electrons in this atom have a principal quantum number of 4? (1)

(c) How many electrons are in the valence shell of this atom? (1)

(d) When this atom is excited, between what atomic orbitals will an electron move for the smallest possible

increase in energy? (1)

Use the aufbau principle to write the ground state electron configuration of an atom of this element. How many of the electrons in this atom have a principal quantum number of 4?