EASY
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Which formula is used for calculating effective nuclear charge?

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Important Questions on Structure of Atom

EASY
If the radius of the hydrogen atom is 53 pm, the radius of the He+ ion is closest to:
HARD
Energy of an electron is given by  E=-2.178×10-18Z2n2 J. Wavelength of light required to excite an electron in a hydrogen atom from level n=1 to n=2 will be :
h=6.62×10-34 Js and c=3.0×108 ms-1
EASY
The radii of the first Bohr orbit of H rH, He+rHe+ and Li2+rLi2+ are in the order
MEDIUM
The energy of an electron in first Bohr's orbit of H atom is 13.6eV. The energy value of electron in the first excited state of Li 2+ is :
EASY
The group number, number of valence electrons, and valency of an element with atomic number 15, respectively, are:
MEDIUM
If the shortest wavelength in Lyman series of hydrogen atom is A, then the longest wavelength in Paschen series of He+ is
MEDIUM
The radius of the second Bohr orbit for hydrogen atom is

(Planck's constant, (h)=6.6262×1034Js; mass of electron =9.1091×10-31kg; charge of electron =1.60210×10-19C; permittivity of vacuum, (0)=8.854185×10-12kg-1m-3A2)
MEDIUM
The ratio of the shortest wavelength of two spectral series of hydrogen spectrum is found to be about 9. The spectral series are:
EASY
Which of the following is the energy of a possible excited state of hydrogen?
MEDIUM
The ground state energy of a hydrogen atom is -13.6 eV. The energy of second excited state of He+ ion in eV is:
MEDIUM

The ionization energy of gaseous Na atoms is 495.5 kJ mol-1. The lowest possible frequency of light that ionizes a sodium atom is 

(h=6.626×10-34 Js, NA=6.022×1023 mol-1)

EASY
How many electrons can fit in each orbital for which n=3 and l=1?
MEDIUM

For any given series of spectral lines of atomic hydrogen, let  Δv-=v-max-v-min  be the difference in maximum and minimum wave number in cm-1

The ratio Δv-Lyman/Δv-Balmar is

EASY
The electron in the hydrogen atom undergoes transition from higher orbitals to orbital of radius 211.6 pm. This transition is associated with
EASY
Which of the following series of transitions in the spectrum of hydrogen atom falls in visible region?
MEDIUM
For the Balmer series, in the spectrum of H atom, v-=RH1n12-1n22, the correct statements among I to IV are,
I As wavelength decreases, the lines in the series converge.
II The integer n1 is equal to 2.
III The lines of the longest wavelength correspond to n2=3.
IV The ionization energy of hydrogen can be calculated from the wave number of these lines.
MEDIUM
The radius of the second Bohr orbit, in terms of the Bohr radius, a0, in Li2+ is:
MEDIUM
If the de Broglie wavelength of the electron in nth Bohr orbit in a hydrogenic atom is equal to 1.5 πa0 (a0 is Bohr radius), then the value of nz is:
MEDIUM
Which one of the following statements is wrong?
EASY
Which is the correct order of increasing energy of the listed orbitals in the atom of titanium?

(At. No. Z = 22)