do dis

 

iron emits K X-ray of energy 6.4 keV & calcium emits K X-ray of energy 3.69 keV calculate d times taken by an iron K  photon & a calcium K photon to cross thru a distance of 3km

 

A radio activ sample at any instant has its disintegration rate 5000 disintegrations/minute . after 5 minutes d rate is 1250 disintegrations/min d decay constant [per minute] is     [ ans: 0.1ln2]  

 

A hydrogen atom in state n=6 makes 2 successive transitions & reaches d ground state. in d 1st transition a photon of 1.13eV is emmitted

a)find d energy of d photon emmitted in d 2nd transition

b)what is d value of n in d intermediate state?

           

Hey,

the second one...

dN/dT=- N

dN/dT=-N"

N/N"=4

(t)=lnN0/N

(T₂-T₁)=ln(4)

 =1/5(ln4)

    .1ln2

=.1ln2.