Which is not a ground state electron configuration?
A. 1s2
B. 1s2 2p1
C. 1s2 2s2
D. 1s2 2s2 2p1
Jerome, or Ivy, it would be easier if you have follow-ups with the original post. If you think someone forgot about you, make a new post with reference to the old. This way there will be better continuity. Thank you.
Follow-up answered in original post:
http://www.jiskha.com/display.cgi?id=1291699279
I know that 1s2 2s2 2p1 is the excited state of 1s2 2s2 but then 1s2 2p1 its orbital are filled out of turn. So I am kinda confused about it because you said that if its excited state then that means its not ground state and if the orbitals are filled out of turn then that's not in the ground state too. So does it mean that b and d are both not in ground state?
"I know that 1s2 2s2 2p1 is the excited state of 1s2 2s2"
Be careful:
1s2 2s2 2p1 (Boron) has 5 electrons, and 1s2 2s2 (Beryllium) has four, so they don't belong to the same element.
The ground state and excited states (of the same element) should have the same number of electrons.
For example, the following are both ground states:
Be 1s2 2s2 (4 electrons)
B 1s2 2s2 2p1 (5 electrons)
For elements with small number of electrons, "filling out of turn", position-wise, is a good guide.
As the number of orbitals increases, sometimes filling an outer orbital requires less or similar energy than completing the remaining shell. For example 4s² would be filled before 3d10 because it takes less energy to do so.
If you'd like all the details, you can go through your textbook, and if you do not have one handy, try:
http://www.wikihow.com/Write-Electron-Configurations-for-Atoms-of-Any-Element
To determine which electron configuration is not a ground state electron configuration, we need to understand what the ground state electron configuration means.
The ground state electron configuration is the arrangement of electrons in an atom's energy levels or atomic orbitals that has the lowest energy. According to the rules of filling the orbitals, electrons fill the lowest energy levels first before moving to higher energy levels.
Let's examine each option:
A. 1s2: This configuration is the ground state electron configuration of a helium atom, which has two electrons. It follows the principle of filling the lowest energy level, which is the 1s orbital.
B. 1s2 2p1: This configuration represents a boron atom, which has five electrons. The first two electrons occupy the 1s orbital, while the third electron goes into the 2s orbital. The remaining two electrons are placed in the 2p orbital. This is a valid ground state electron configuration for boron.
C. 1s2 2s2: This configuration represents a beryllium atom, which has four electrons. The first two electrons occupy the 1s orbital, and the next two electrons go into the 2s orbital. This is a valid ground state electron configuration for beryllium.
D. 1s2 2s2 2p1: This configuration represents a lithium atom, which has three electrons. The first two electrons occupy the 1s orbital, the next two electrons occupy the 2s orbital, and the last electron is in the 2p orbital. This is also a valid ground state electron configuration for lithium.
Therefore, all the provided options (A, B, C, and D) represent ground state electron configurations. None of them is not a ground state electron configuration, so the answer is none of the above.