Which electron cannot occurr?
a) 1s^22s^1
b) 1s^2 2s^2 2p^6 3s^2
c) 1s^2 1p^6 2s^2 2p^6
d) all can occurr
How do I figure this out?
s orbitals can contain 2 electrons maximum and p orbitals can contain 6. I do not see this condition being violated in any of the configurations you have listed. .
A is ok. B is ok. C is not ok since you may NOT have a 1p electron. Only s electrons may occur in the N = 1 level. I hope this helps.
DrBob is correct. No p orbitals are allowed in the n=1 "shell". n=2 can have s and p orbital electrons. n=3 can have s, p and d, etc. The different lower case letters that are used to designate orbitals were chosen for obscure reasons having to do with spectroscopy. As quantum mechanics began to explain the reasons for these rules, is became clear that the s, p, d, f etc orbitals have different integral multiples of h/(2 pi) for the electron angular momentum.
To answer this question, you need to understand the rules for electron configurations. The electron configuration describes the distribution of electrons in the different energy levels and orbitals of an atom.
The electron configuration notation follows the pattern of "nS^m", where n represents the principal energy level, S represents the orbital type (s, p, d, f), and m represents the number of electrons in that orbital.
In this case, we need to determine which electron configuration is not possible.
Let's analyze each option:
a) 1s^22s^1 - This configuration is possible. The first energy level (n = 1) has 2 electrons in the 1s orbital and the second energy level (n = 2) has 1 electron in the 2s orbital.
b) 1s^2 2s^2 2p^6 3s^2 - This configuration is possible. The first energy level (n = 1) has 2 electrons in the 1s orbital, the second energy level (n = 2) has 2 electrons in the 2s orbital and 6 electrons in the 2p orbital, and the third energy level (n = 3) has 2 electrons in the 3s orbital.
c) 1s^2 1p^6 2s^2 2p^6 - This configuration is not possible. The first energy level (n = 1) can only have s orbitals, so there cannot be any p electrons in this level.
d) all can occur - This statement is not true since we have determined that option c) is not possible.
Therefore, the correct answer is c) 1s^2 1p^6 2s^2 2p^6.