Structure of Atom

Heat treatment of muscular pain involves radiation of wavelength of about 900 nm. Which spectral line of H atom is suitable for this? Given : Rydberg constant RH = 105 cm-1, h = 6.6 10-34 J s, c = 3 108 m/s

1. Lyman series, 1
2. Balmer series, 2
3. Paschen series, 5 3
4. Paschen series, 3

Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :

1. Both Statement I and Statement II are true
2. Both Statement I and Statement II are false
3. Statement I is false but Statement II is true
4. Statement I is true but Statement II is false

Given below are two statements about X-ray spectra of elements : In the light of the above statements, choose the correct answer from the options given below :

1. Statement I is false but Statement II is true
2. Both Statement I and Statement II are true
3. Statement I is true but Statement II is false
4. Both Statement I and Statement II are false

Radius of the first excited state of Helium ion is given as : a0 radius of first stationary state of hydrogen atom.

1. r = a04
2. r = 2a0
3. r = 4a0
4. r = a02

Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :

1. Statement I is false but Statement II is true
2. Both Statement I and Statement II are false
3. Statement I is true but Statement II is false
4. Both Statement I and Statement II are true

Niobium (Nb) and ruthenium (Ru) have “x” and “y” number of electrons in their respective 4 d orbitals. The value of x+y is .