how can i tell if an electron configuration represents a atom in an excited state

Question

wolfe8 · Answer

Welcome to OpenStudy. I would say, you will have more electrons in the higher shells than lower?

anonymous · Answer

i agree with @wolfe8

anonymous · Answer

thanks @wolfe8 but the whole shell thing confuses me. My teacher displays the configuration  like this--> 2-8-18-6. how can i tell if it is excited from that?

wolfe8 · Answer

Ok first I need to know what grade you are in so I know I am doing this right.

anonymous · Answer

10th Grade @wolfe8

wolfe8 · Answer

Odd. I'm not sure how to tell just form that. Can I know how the question actually goes?

anonymous · Answer

which electron configuration represents a selenium atom in an excited state?
1)2-7-18-6  2)2-7-18-7    3)2-8-18-6     4)2-8-18-7

anonymous · Answer

2-8-18-6 is ground

wolfe8 · Answer

Ah so like I said, you will have some electron move from the lower shell to the higher shell. From left to right the shells are further from the nucleus. So you will have less on the left-er shell and more on a right-er shell as compared to the ground state. Does that make sense?

anonymous · Answer

i think i follow what youre saying. so that would mean 2-8 would turn into 2-7 correct?

wolfe8 · Answer

Right. In B, one electron from the second shell moved to the fourth shell, showing that that electron is excited to a higher energy level.

anonymous · Answer

Yeah i figured it out now. Thank you very much for your help. I appreciate it.

wolfe8 · Answer

You're welcome. Welcome to OpenStudy again. Do take time to read our CoC: http://openstudy.com/code-of-conduct and enjoy your stay. If you are satisfied with any question, please reward a medal to whoever you think deserves it and close the question. We also have a fan and testimony system. See you around :)