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Several South Indian states raise 2-3 cr...

Several South Indian states raise 2-3 crops of rice annually.The agronomic feature that makes this possible is because of

A

shorter rice plant

B

better irrigation facilities

C

early yielding rice variety

D

disease resistant rice variety

Text Solution

Verified by Experts

The correct Answer is:
c
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The electron in a hydrogen atom makes a transition n_1 to n_2 , where n_1 and n_2 are the principal quantum numbers of the two states. According to the Bohr model , the time period of revolution of electron in initial state is 8 times that in the final state. Which are possible values of n_1 and n_2 ? A 4,2 , B 8,2 , C 8,1 ,D 6,3 .

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H, He^(+), Li^(2+) are examples of atoms or ions with one electron each . The energy of such atoms when in the n-th energy state (according to Bohr,s theory , n=1,2,3…. =principal quantum number ) is E_n =(-13.6 Z^2)/(n^2) eV (1 eV =1.6xx10^(-19)J) . For the ground state ,n=1 . in order to raise the atom from the ground state to n=f , the suitable incident light should have a wavelength given by lambda=(hc)/(E_f-E_1) . But the atom cannot stay permanently in the f-energy state, ultimately , it comes to the ground state by radiating the extra energy , E_f-E_1 as electromagnetic radiation . The electron of the atom comes from n=f to n=1 in one or more steps using the permitted energy levels . As a result there is a possibility of emission of radiation with more than one wavelength from the atom. Planck's constant =6.63 xx10^(-34)J*s and velocity of light c=3xx10^(8)m*s^(-1) . Energy of which quantum state of He^+ ion will be equal to the ground level energy of hydrogen ?

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