Quantum Numbers

What are quantum numbers?

a set of four numbers that completely describe the location and the energy for each electron.

What 4 things do quantum numbers tell us?

1. Distance from nucleus

2. Shape

3. Position

4. Spin

Tell what the 4 quantum numbers represent

First: principal energy level of the electron.

Second: Sublevel (shape) s,p,d,f

Third: electron position within the sublevel

Fourth: Spin of the electrons

What is the principle quantum number (n)?

It is the first number and identifies the principle energy level - it indicates the average or most likely distance from the nucleus where the electron resides - positive integers only

What is the maximum number of electrons that can be found in an energy level?

2n²

What does n represent in the formula 2n²?

n represents the principle energy level

What is the second quantum number(I)?

the second number indicates the sublevel - can only be numbers 0-3 and must be smaller than the first number

What are the four different energy sublevels?

s, p, d, and f They describe the different shape that the orbitals can have

What number represents the s sublevels?

0

What number represents the p sublevel

1

What number represents the d sublevel?

2

What number represents the f sublevel?

3

What is the third quantum number (ml)

describes the electron position within the sublevel or orbital - it must be equal to or smaller than the second number

How many possible orbitals in s, p, d and f?

s-1, 0

p-3 -1,0,1

d-5 -2,-1,0,1,2

f-7 -3,-2,-1,0,1,2,3

How many different numbers can the third quantum number be?

-3 through 3

-3,-2,-1,0,1,2,3

What is the rule about the second number related to the first number? An the third number related to the second number?

The second number must be smaller than the first number. The third number must be the same or smaller than the second number

What is the fourth quantum number (ms)

Spin of the electrons

either 1/2 for counter clockwise or -1/2 for clockwise spin

T/F No two electrons in the same atom have the same 4 quantum numbers

True - they will always have at least one different because they cannot both spin the same direction.

How many electrons can be present in each orbital?

2 electrons

s- there are only 2 electrons because there is 1 orbital

p- there are 6 because there are 3 orbitals

d- there are 10 because there are 5 orbitals

f- there are 14 because there are 7 orbitals