Understanding Shells' Arrangement

  • Thread starter Jadaav
  • Start date
In summary, the 1st shell only can have 2 electrons in it because that is the number that is associated with the principal quantum number n=1. Sub-shells are orbitals, determined by quantum numbers in Schrodinger's equations. n is the principal quantum number that determines the shell. l has something to do with angular momentum, m is the magnetic angular quantum number.
  • #1
Jadaav
175
1
Hi,

Why does the 1st shell only can have 2 electrons in it ?

Also what are sub-shells ?
 
Chemistry news on Phys.org
  • #2
Jadaav said:
Hi,

Why does the 1st shell only can have 2 electrons in it ?

The Pauli exclusion principle says electrons in atoms cannot share the same 4 quantum numbers. The fact that the electrons are in the 1st shell determines 3 of them (n=1, l=0, ml=0), and there are only two possible values for the 4th quantum number (ms=+1/2 and ms=+1/2). Got it?

Also what are sub-shells ?

Well, for principal quantum numbers higher than n=1, there are multiple possibilities for the value of the angular momentum quantum number l (l=0 up to l=n-1). Each possible value of l is associated with a sub-shell: l=0 is called the s-subshell, l=1 is called the p-subshell, and so on.
 
  • #3
What is the quantum number ?

and n,I and m ?
 
  • #4
Jadaav said:
What is the quantum number ?

and n,I and m ?

The quantum number is something you should already know about if you are asking the question in your original post :wink:. Seriously though, please look that up on wikipedia to get the basics down, then come back here and ask specific questions if you are confused.
 
  • #5
To know that, you need to learn quantum mechanics a little bit. Sub-shells are orbitals, determined by quantum numbers in Schrodinger's equations. n is the principal quantum number that determines the shell. l has something to do with angular momentum, m is the magnetic angular quantum number.

In general, l must be less than n, while m must be equal to or less than l. In the first shell n=1 as it is the first shell, l only =0. In the second shell where n=2, l=0 or 1, so m=+1 or -1 or 0. For each set of parameters there is one orbital and in one orbital there are two electrons. Thus in first shell there is only on orbital possible, thus 2 electrons.

I hope this would help you with your question.
 
  • #6
ZealScience said:
To know that, you need to learn quantum mechanics a little bit. Sub-shells are orbitals, determined by quantum numbers in Schrodinger's equations. n is the principal quantum number that determines the shell. l has something to do with angular momentum, m is the magnetic angular quantum number.

In general, l must be less than n, while m must be equal to or less than l. In the first shell n=1 as it is the first shell, l only =0. In the second shell where n=2, l=0 or 1, so m=+1 or -1 or 0. For each set of parameters there is one orbital and in one orbital there are two electrons. Thus in first shell there is only on orbital possible, thus 2 electrons.

I hope this would help you with your question.

OK, thanks I'm going to learn quantum mechanics first.
 

FAQ: Understanding Shells' Arrangement

What is the arrangement of shells in an atom?

The arrangement of shells in an atom is a series of concentric energy levels or orbitals. These shells are numbered starting from the innermost shell, with the first shell being closest to the nucleus.

How many shells are there in an atom?

The number of shells in an atom depends on the element and the number of electrons it has. Generally, the number of shells increases as you move down the periodic table. For example, hydrogen has one shell, while uranium has seven.

Why do shells in an atom have different energy levels?

Shells in an atom have different energy levels because of the attraction between the negatively charged electrons and the positively charged nucleus. The further away an electron is from the nucleus, the higher its energy level will be.

What is the maximum number of electrons that can occupy a shell?

The maximum number of electrons that can occupy a shell is determined by the formula 2n^2, where n is the number of the shell. For example, the first shell can hold a maximum of 2 electrons (2 x 1^2), while the second shell can hold a maximum of 8 electrons (2 x 2^2).

How does the arrangement of shells affect the chemical properties of an element?

The arrangement of shells affects the chemical properties of an element by determining how easily its electrons can be gained or lost. Elements with full outer shells tend to be stable and less reactive, while those with partially filled outer shells are more reactive and likely to form chemical bonds with other elements.

Similar threads

Why do atoms want to complete their shells?
Replies
6
Views
2K
Selection rules in electron transitions
Replies
2
Views
1K
Chemistry Understanding the concept of electron per shell
Replies
5
Views
1K
What's the chemistry behind a semiconductor?
Replies
8
Views
1K
Why Does Ionization Energy Increase Differently Between Orbital Types?
Replies
9
Views
1K
How is PbBr2 an ionic compound?
Replies
2
Views
6K
Why do shells begin to hold more electrons?
Replies
5
Views
2K
I Shell structure topological defects as substitute for dark matter
Replies
3
Views
818
I The claymath 4-d QFT problem and virtual particles (as an example)
2
Replies
36
Views
2K
Where Does the Energy for Ionic Bonding Come From?
Replies
8
Views
2K

Hot Threads

Recent Insights

Back
Top