Calculate the wavelength of the spectral line obtained in the spectrum of $$Li^{2+}$$ ion when the transition takes place between two levels whose sum is 4 & the difference is 2.

Question

maheshmeghwal9 · Answer

I know this formula: -$$\frac{1}{\lambda}=R \times Z^2 \times [\frac{1}{n_1^2}-\frac{1}{n_2^2}].$$Where $$n_2>n_1.$$

maheshmeghwal9 · Answer

Therefore I took the question as
$$n_2+n_1=4$$$$n_2-n_1=2.$$

maheshmeghwal9 · Answer

I gt $$n_2=3; \space \space n_1=1.$$

maheshmeghwal9 · Answer

but when I put these values in the formulae 
I didn't gt answer.

maheshmeghwal9 · Answer

I know this too: -
$$Li^{2+}.$$
$$Z=3.$$

maheshmeghwal9 · Answer

So anybody plz help me:)

maheshmeghwal9 · Answer

@mukushla @mathslover @vishweshshrimali5 @PaxPolaris @UnkleRhaukus @A.Avinash_Goutham @JFraser Please help:)

paxpolaris · Answer

I didn't even know lithium mad a 2+ ion ... :S

maheshmeghwal9 · Answer

ohhhh

vishweshshrimali5 · Answer

U can atleast find the transition i.e. lower and upper level 

i mean initial and final energy level by simple maths

vishweshshrimali5 · Answer

what do you get the value of lower and highest energy level for transition

maheshmeghwal9 · Answer

I have given that above:)

vishweshshrimali5 · Answer

sorry didn't read that

maheshmeghwal9 · Answer

np:)

vishweshshrimali5 · Answer

u have done everything correctly 

ur answer should be correct

maheshmeghwal9 · Answer

oh ok
but would u also give me the answer plz?
so i can match mine.

vishweshshrimali5 · Answer

I would have to calculate wait

maheshmeghwal9 · Answer

ok:)

vishweshshrimali5 · Answer

what did u take the value of R = ?

maheshmeghwal9 · Answer

R=109667 cm^-1

paxpolaris · Answer

i got 11.4 nm http://lmgtfy.com/?q=1%2F8%2F(Rydberg+Constant)

maheshmeghwal9 · Answer

But answer given is 
1.14 x 10^-6 cm.

paxpolaris · Answer

that's the same...

maheshmeghwal9 · Answer

oh ok

maheshmeghwal9 · Answer

But how?

paxpolaris · Answer

http://lmgtfy.com/?q=1%2F8%2F(Rydberg+Constant)+in+cm

vishweshshrimali5 · Answer

yes

$$1.14 * 10^{-6} cm = 1.14 * 10^{-8} m = 11.4 * 10 ^{-9} m = 11.4 nm$$

ujjwal · Answer

Its 11.4 nm
Put R=10973731.57 and that's it.

maheshmeghwal9 · Answer

But R = 109667 cm^{-1}

vishweshshrimali5 · Answer

http://bit.ly/NcPY8j

paxpolaris · Answer

there are 10^7 nanometers in 1 centimeter
11.4nm = 1.14x10^-6 cm

maheshmeghwal9 · Answer

oh ya i gt my answer
by R =109677 cm^{-1}
Thanx to all :D

vishweshshrimali5 · Answer

:D

paxpolaris · Answer

not that it matter for this question ... I took R=109737 cm^{-1} http://lmgtfy.com/?q=(Rydberg+Constant)+%20in+cm%5E-1