DAT Gen Chem (Quantum numbers)

If l=3

Ml= -3,-2,-1,0,1,2,3 and the number of orbital in the subshell is 7. This falls into the S,P,D, and F orbitals.

If l=1

Ml=-1,0,1 and the number of orbitals in the subshell is 3. This falls into the S and P orbitals

If l=2

Ml=-2,-1,0,1,2 and the number of orbitals in the subshell is 5. This falls into the S,P, and D orbitals.

If l=0

Ml=0 and the number of orbitals in the subshell is 1 and this falls in the S orbital

The 4 quantum numbers

No two electrons can share the same combination of 4 quantum numbers

Can an electron with an ms value of 1/2 have a downward spin?

No, the positive value is ONLY synonymous with a spin up.

Is it possible to have an electron with the following values: n=2, l=1, ml=3, ms=1/2

No, this configuration is not possible because ml=3 is not in the range or -1 to 1.

How many subshells are in the principal quantum level n=3?

The are three subshells in the principal quantum level n=3

Hund's Rule

This states that electrons fill one at a time and you must fill each shell with one electron before completely filling the rest. -Electrons are negative and will try to repel each other which is why there is a need for the partial positive and negatives in the shells.

The number of values of the orbital angular number l can also be used to identify the number of subshells in a principal electron shell

When n=1, l=0 and has one subshell When n=2, l=0,1 and has two subshells When n=3, l=0,1,2 and has 3 subshells

Is it possible to have two electrons with the same n,l, and ml values?

Yes, it is possible to have two with the same number. however, the value of the ms must have one with a =1/2 or -1/2 and the other one must be opposite this value.

The 4 quantum numbers

designate: Levels, subshells, orbitals, and spin of electrons

The 4 quantum numbers

help determine the electron configuration of and atom and the probable location of an atoms electrons

If n=7, what are the possible values of l?

l=n-1, so 7-1=6. This leaves the possible values of l to be: 0,1,2,3,4,5,6

Principal Value and Subshells

n=1, one S subshell (l=0) n=2, one S and one P Subshell (l=1) n=3, one S, one P, and one D Subshell (l=2)

The 4 quantum numbers

were developed to better understand the movement and pathway of electrons in its designated orbital

The principal quantum number (n)

-All orbitals with the same n value are in the same principal level -When the number is higher the number of principal electronic shells is higher -The higher the number the further the distance between the nucleus and the electron -When the principal number increases the atom and the atomic radius increase. -With the higher number there is a greater ease to expel the electron because of the weaker pull on it. This in turn decreases the ionization energy

The principal quantum number (n)

-Describes the energy of an electron -Describes the probable distance of the electron from the nucleus -Designates the principal electron shell -Since n is the probable distance from the nucleus, the larger the "n" the further the distance from the nucleus, the larger the size of the orbital, and larger the size of the atom

Orbital Angular Quantum Number (l)

-Describes the shape and the angular distribution of an orbital -The number of angular nodes=angular momentum quantum number (l) -Each "l" value corresponds to a specific s,p,d,&f subshell (the unique shape) -"l" can be equal to 0, but unlike n, l cannot be larger than one less the principal number (n-1).

Magnetic Quantum Number (Ml)

-Determines the number of orbitals and their orientation within the subshell -The value of Ml depends on the value of l -Given a certain l, Ml is a value from -1 to +1 which includes 0.

Electron Spin Quantum Number (Ms)

-The Spin Quantum number does not depend on any other quantum number -It is represented by -1/2 and +1/2 and this is the direction of the electronic spin -+1/2 is up and -1/2 is down -The spin quantum number is the determination of an atoms ability to generate a magnetic field.

Orbitals

-The number of orbitals is equal to the number of values the magnetic (Ml) quantum number takes on. -2l+1: Is the equation to figure out the number of orbitals in a subshell, it does not give you the Ml value, but the possible number of values Ml can take on in a particular orbital

The principal quantum number (n)

-n can be any positive integer and n=1 designated the first principal energy shell. -The first energy shell has the lowest energy state aka the ground state. -"n" cannot be zero or a negative number because there is not an atom that can have a zero or negative energy state -When electrons become excited they jump/absorb energy (photons) and go to the next energy shell. From n=1 to n=2, energy was absorbed. -When electrons jump down energy levels they emit energy(photons), from n=3 to n=2, energy was expelled/emitted. -as the energy of the electron increases, so does the principal quantum number

What is the name of the orbital with quantum numbers n=4 and l=1

4P because 4 is the principal quantum number and the l=1 is equivalent to the p subshell.

Heisenberg Uncertainty Principle

According to the Heisenberg Uncertainty principle, you cannot know the exact location and momentum of an electron at a given time. -When one becomes more certain, the other one becomes more uncertain and vice versa. -Ex. If one becomes more certain of the momentum of an electron at a given point, its location becomes more less certain. -This principle also explains why n has to be a whole number and not a partial number. If there were to be partial waves and whole waves, they would cancel each other out. The crest of one wave and the trough of another wave would cancel out and the particle would not move.

The 4 quantum numbers

Also describe the characteristics of the electrons in atoms

What is the name of the orbital(s) with the n=3 number.

Because n=3 that gives us 3 choices since the l value is unknown. This gives us 3s,3p, and 3d.

If l=1, what is Ml and how many orbital values are possible?

For the equation 2l+1, you plug in the 1 for L and get 3 possible ml values in the particular orbital. The possible values are -1,0,1.

Suppose that the principle quantum number is 3, what are the possible values for the other four numbers?

If n=3, then you have to figure out l by doing n-1, so 3-1=2. This gives the possible values of l (Since there must be 3)= to 0,1,&2. So, the answers would be: -n=3, l=0, ml=0, ms=-1/2 or +1/2 -n=3, l=1, ml=-1,0, or 1, ms=-1/2 or +1/2 -n=3, l=2, ml=-2,-1,-,1,2 ms=-1/2 or+1/2

Pauli Exclusion Principle

Pauli discovered that a set of quantum numbers is specific to each electron and no two electrons can have the same n,l,ml, and ms values. While the first three quantum numbers can have the same values and identify a specific orbital, the ms value is specific and must have opposite spins.

Name of Subshell and the Value of l

S Subshell= 0, l value P Subshell=1, l value D Subshell=2, l value F Subshell=3, l value

If n=3 and l=2, what are the possible values of Ml?

Since Ml must range from -1 to +1 the values of Ml are -2,-1,0,1,or 2

What type of orbital is designated by the quantum numbers n=4, l=3, and ml=0?

Since the l=3 is representative of the f subshell, this would be a 4f orbital.

If l=4, how many angular nodes does the atom have?

Since the number of angular nodes is equal to the value of l, the atom has 4 angular nodes.

List the possible combinations of all four quantum numbers when n=2, l=1, ml=0 and ms.

The fourth number is independent of the first three, so the first three will remain the same. The possible combinations are: -n=2, l=1, ml=0 and ms=+1/2 -n=2, l=1, ml=0 and ms=-1/2

Which orbital has the higher ionization energy? The one with n=3 or n=2?

The one with n=2 because it is closer to the nucleus and requires more energy to remove an electron.

The 4 quantum numbers are

The principal quantum number (n) The orbital quantum number (l) The magnetic quantum number (Ml) The spin quantum number (Ms)