TEXTBOOK 1D.23

[Jessy Ji 2J]

For this question, for part c, it asks how many orbitals can have the quantum number n=2. I thought the answer would be two because l can only be numbers less than n-1. So in this case, l can only be 0 and 1. But the answer in the back of the textbook says the answer is 4. So I am kind of confused. Can anyone explain that for me please.

Thank you

[Henry_2A]

Hi!

An orbital requires the values n, l, and ml. For n =2, you're right in that it includes l = 0 and l =1. However, you also need to consider the magnetic quantum number. For l = 0, ml = 0 can exist. For l=1, ml = -1,0,+1 can exist.

Thus, there are a total of four orbitals.
n=2, l = 0, ml = 0
n=2, l = 1, ml = -1
n=2, l= 1, ml = 0
n2, l = 1, ml = +1

I hope this helps

[Jericho Ansay 1C]

Hi, for the quantum number n = 2, you would just have to consider the 2s orbital and the 2p orbitals. You would know that there exists one 2s orbitals and three 2p orbitals, which would give you a total of 4 orbitals. Hope this helps!

[Kaethe Zappacosta 2L]

Hi! So if n=2, l can be 0 or 1. However, l is not the answer to how many orbitals; it just tells us that there can be 2s and 2p sub-shells. The 2s subshell has 1 orbital, and the 2p subshell has 3 orbitals, so the total is 4.

[arielle_cunanan3K]

Hi so in this energy level, n=2, there are a 2s and 2p sub shell. Since there is one orbital in the 2s subshell and three orbitals in the 2p subshell, there are 4 total orbitals in all

[Michelle Li 2B]

For the quantum number n=2, l can either equal 0 or 1, since l is equal to values from 0 to (n-1). Therefore, for l=0, there is only one orbital because ml = 1. For l=1, there are 3 orbitals because ml = -1, 0, +1. Thus, since 1 + 3 = 4, there are 4 total orbitals.

[Kurosh Zamiri 1I]

Hi! I tried to think of this question as simply as possible so I thought of it this way. With n=2, this leaves the values of l as l=0 or l=1. The s sub-shell corresponds to l=0, and the p sub-shell corresponds to l=1. We know that the s sub-shell has 1 orbital, while the p sub-shell has 3 orbitals. Therefore, a value of n=2 has 4 orbitals! Hope this helps!