[qijino1236]

Just started watching Khan Acedemy chemistry videos and I have a question about electron configuration...

What electrons are in the outermost shell(what are the valence electrons)?
Example: titanium electron configuration:
1s2 2s2 2p6 3s2 3p6 4s2 3d2 
4s2 is the outermost shell correct? …
My question is is 3d2 the highest energy level?
And what does it really mean to have the highest energy level?
From the videos on Khan acedemy I think he said 3d2 has the highest level but I wonder about this because:
He also said in an earlier video that the further away from the nucleus of the atom, the higher the energy level, so wouldn't it be the outermost shell(4s2 which I am assuming is the furthest away from the nucleus) that has the highest energy level?
And any other conclusions that could be made from this electron configuration?

[stanley002]

first: you´re right, 3d2 is the highest level.
But don´t order the energetiv levels this way.
Here´s a link of the correct energetig order http://www.google.com/imgres?um=1&hl=de&client=firefox-a&sa=N&rls=org.mozilla:de:official&biw=1680&bih=948&tbm=isch&tbnid=Bxwgzbc46zp60M:&imgrefurl=http://mageechem11.blogspot.com/2012/04/electronic-structure-of-atom.html&docid=zAN_8CBXtc0naM&imgurl=http://1.bp.blogspot.com/-YXubAv8I2nU/T5X4LmtsfCI/AAAAAAAAAAg/r2KsPTwnCdQ/s1600/elecfill.gif&w=350&h=311&ei=pVcRUJi4FsjZtAb9_oCwAQ&zoom=1&iact=rc&dur=433&sig=111348203562597835039&page=1&tbnh=145&tbnw=163&start=0&ndsp=41&ved=1t:429,r:20,s:0,i:136&tx=83&ty=66

[vansh123]

yes 4s2 is the outermost shell
the energy level are in the way of the aufbau principle
http://upload.wikimedia.org/wikipedia/commons/9/95/Klechkovski_rule.svg
There is a rule which is called (n+L) which states that orbital which has the least value n+L will be filled first with electrons which means that it is nearest to the nucleus and as n+L increases the distance also increases btw the nucleus and the orbital
i think this could help you for now

[camptzak]

Just started watching Khan Acedemy chemistry videos and I have a question about electron configuration...

What electrons are in the outermost shell(what are the valence electrons)?
Example: titanium electron configuration:
1s2 2s2 2p6 3s2 3p6 4s2 3d2 
4s2 is the outermost shell correct? …
My question is is 3d2 the highest energy level?
And what does it really mean to have the highest energy level?
From the videos on Khan acedemy I think he said 3d2 has the highest level but I wonder about this because:
He also said in an earlier video that the further away from the nucleus of the atom, the higher the energy level, so wouldn't it be the outermost shell(4s2 which I am assuming is the furthest away from the nucleus) that has the highest energy level?
And any other conclusions that could be made from this electron configuration?

Wow, It makes me really happy to see someone in highschool using their free time to explore physics and chemistry!
For now people will give you pictures and basic formulas that show the order of the energy levels of the electron shells. I can see that you dont want to be just told, you want someone to give mathematical proof that is grounded in principles that you understand.  To really understand why the 4s is less than the 3d you need to have a good understanding of quantum mechanics, which is to understand the mechanics of light and the mechanics of elctrons as they occupy space around the atom.
Unfortunatley there were only two people (Albert Einstein and Erwin Schrodinger) who really truly understood quatum mechanics, and they are both dead now
So, in short, I know these charts are not telling you what you really want to know. The only thing that really can tell you is your physics textbook and that mass of tissue sitting in fluid in your cranium.