Week 5: 3.5 Quantum Numbers

Which of the following statements about the principal quantum number, n, are true?

-The higher the value of n, the greater the total energy of the electron. -The higher the value of n, the farther the average distance to the nucleus.

If l=0,ml must be:

0 -Zero would be the only allowed value in this instance since if l=0, then the electron has an s orbital (spherical shape) and does not have any angular momentum (i.e. vector does not point in any direction). Therefore, if l= 0 then ml must also = 0.

An electron in a 4s orbital must have an ml value of:

0 An s orbital must have an l value of zero, so the ml value must also be zero.

An electron in a 3d orbital may have an ms value of:

1/2 -The only allowed values for spin, regardless of orbital, are 12 and −12.

Given the following quantum numbers: subshell = 2p,l=1,ml=−1,0,1, what is the principle quantum number?

2 -Another name for the principal quantum number is the shell number, so if the subshell is 2p, the the principle quantum number will be 2.

Which of the following formulas gives us the total number of possible orbitals with the same value of l?

2l+1 - gives us the total number of possible orbitals with the same value as l. For example, the p orbital has a value of l=1. This means there can be three p orbitals, (2⋅1)+1.

An electron in a 3p orbital must have an n value of:

3

An electron in a 5f orbital must have an l value of:

3 -It is an l value of 3 that specifically describes all f orbitals.

How many electrons can the n=4 energy level hold?

32 l=0 holds 2 electrons, l=1 holds 6 electrons, l=2 holds 10 electrons, l=3 holds 14 electrons

How many orbitals are in the subshell with the following quantum numbers: n=4,l=2,ml=−2,−1,0,1,2?

5 l=2 and ml=−2,−1,0,1,2 indicate five possible orbitals in the subshell.

The principal quantum number can help define what aspect of the electron?

It's energy

The ________ states that no two electrons in the same atom can have exactly the same set of all four quantum numbers.

Pauli Exclusion Principle

The magnetic quantum number, ml, corresponds to which of the following?

an individual orbital's orientation within a subshell

Orbitals with l=2 are called ______ orbitals.

d

An angular momentum quantum number of l=2 indicates what type of orbital?

d -The angular momentum quantum number is denoted by the symbol l. It is an integer that defines the shape of the orbital, and takes on the values l=0,1,2,...,n−1.

Every ________ will have its own unique set of quantum numbers.

individual electron

Which of the following formulas gives us ml, the total number of possible orbitals within a subshell?

ml=2l+1 The magnetic quantum number, gives us the total number of possible orbitals within a particular subshell.

Which of the following quantum numbers does NOT define orbitals?

ms -describes the intrinsic electron property known as "spin,"

Which electron spin state has the lower energy in the absence of an external magnetic field?

ms=+12 and ms=−12 have the same energy.

Which set of quantum numbers is invalid?

n=0,l=0,ml=0,ms=12 The principal quantum number, n, must be at least 1.

Which of the following subshells, indicated by the quantum numbers listed, is characterized by the highest energy?

n=4,l=2 - The quantum number n tells us the principal energy level, which primarily determines the energy of the electron(s) that inhabit(s) it

Orbitals with l=1 are called _____ orbitals.

p

Given the following quantum numbers n=4,l=1,ml=−1,0,1, what is the subshell of the orbital?

p For ml values of −1,0 and +1, there are three possible orbitals in the shell which indicates a p subshell.

Orbitals with l=0 are called _____ orbitals.

s

Which of the following describes an intrinsic electron rotation?

spin quantum number, ms

The angular momentum quantum number, l, corresponds to:

the type (or shape) of orbital the electron resides in