Among the following electrons, which has highest energy?
a. n = 3, l = 2, m = 0, s = + 1/2
b. n = 4, l = 0. m= 0 , s = - 1/s
answer is A.
but i want to know that how to get this answer help please?
Memory
1s
2s 2p6
3s2 3p6 4s2 3d10
So in your example, the answer b has a 4s electron
and answer a has a 3d electron (l=2).
See this: http://www.edu.pe.ca/kish/grassroots/chem/Level.gif
and this more complicated discussion:
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCAQFjAA&url=http%3A%2F%2Fwww.angelo.edu%2Ffaculty%2Fkboudrea%2Fgeneral%2Fquantum_numbers%2FQuantum_Numbers.doc&ei=m7AuVJKBDanE8AHO5ICoDw&usg=AFQjCNG5qgvCn3rzQ4uwdlJkiAMpth20Aw&sig2=bfbamJ0vzDn9oIjzjpV2Uw&bvm=bv.76802529,d.b2U&cad=rja
@bobpursley . THanks , but tell me , what will happen if we will choose answer which has +1/2 . will this technique work for quick solution help?
spin 1/2, and -1/2 are same energy state. it is the orbital levels that determine energy state.
If you are studying for the MCAT, you need a basic review of quantum states in atoms.
@bobpursley , yeah i am preparing for mcat and only 10 days are left, i have dozens of books but i am still confused in chemistry , specially organic chemistry and physical chemistry , time is also short , any tip?
To determine which electron has the highest energy, we need to consider the quantum numbers associated with each electron.
The energy of an electron depends on its principal quantum number (n) and the azimuthal quantum number (l). Generally, the higher the value of n, the higher the energy level. However, within a given value of n, the energy level increases as the azimuthal quantum number (l) increases.
Let's compare the given electrons:
a. n = 3, l = 2, m = 0, s = + 1/2
b. n = 4, l = 0, m = 0, s = - 1/2
For electron a, the principal quantum number (n) is 3, and the azimuthal quantum number (l) is 2. For electron b, the principal quantum number (n) is 4, and the azimuthal quantum number (l) is 0.
Since electron b has a higher value of n (4) compared to electron a (3), electron b is in a higher energy level. However, within each energy level, the energy increases as the azimuthal quantum number (l) increases.
In this case, electron a has a higher azimuthal quantum number (l=2), while electron b has a lower azimuthal quantum number (l=0). Therefore, electron a has a higher energy level compared to electron b.
Hence, the correct answer is option A, electron a has the highest energy.