General
✓✗Which orbital is filled immediately after 4s?
- 3d
- 4d
- 5s
- 4p
General
✓✗The series limit of the Balmer series of hydrogen corresponds to the transition
- n = ∞ → n = 2
- n = ∞ → n = 1
- n = 3 → n = 2
- n = 2 → n = 1
General
✓✗The wave nature of electrons was experimentally confirmed by
- the alpha scattering experiment
- cathode rays
- electron diffraction
- the photoelectric effect
General
✓✗The longest wavelength in the Lyman series of hydrogen is about (RH = 1.097 × 107 m−1)
- 102.6 nm
- 656 nm
- 91.2 nm
- 121.6 nm
General
✓✗The energies and radii of the first Bohr orbits of He+ and Li2+ are (RH = 2.18 × 10−18 J, a0 = 52.9 pm)
- E(Li2+) = −19.62 × 10−16 J, r(Li2+) = 17.6 pm; E(He+) = −8.72 × 10−16 J, r(He+) = 26.4 pm
- E(Li2+) = −8.72 × 10−18 J, r(Li2+) = 26.4 pm; E(He+) = −19.62 × 10−18 J, r(He+) = 17.6 pm
- E(Li2+) = −19.62 × 10−18 J, r(Li2+) = 17.6 pm; E(He+) = −8.72 × 10−18 J, r(He+) = 26.4 pm
- E(Li2+) = −8.72 × 10−16 J, r(Li2+) = 17.6 pm; E(He+) = −19.62 × 10−16 J, r(He+) = 17.6 pm
General
✓✗How many electrons in an atom can have n = 3, l = 2 and ms = −1/2?
- 3
- 5
- 2
- 10
General
✓✗146C and 168O are
- isotones
- isoelectronic
- isotopes
- isobars
General
✓✗The de Broglie wavelength of an electron with kinetic energy 54 eV is about (h = 6.626 × 10−34 J s, me = 9.1 × 10−31 kg) (1 eV = 1.602 × 10−19 J)
- 0.54 nm
- 1.67 nm
- 0.167 nm
- 0.0167 nm
General
✓✗Be2+ is isoelectronic with which of the following ions?
- Mg2+
- Na+
- Li+
- H+
General
✓✗If n = 6, the correct sequence for filling of electrons will be
- ns → (n − 2)f → (n − 1)d → np
- ns → (n − 2)f → np → (n − 1)d
- ns → (n − 1)d → (n − 2)f → np
- ns → np → (n − 1)d → (n − 2)f
General
✓✗The charge on an electron was determined by
- E. Rutherford (alpha scattering)
- J. Chadwick (beryllium bombardment)
- J. J. Thomson (cathode rays)
- R. A. Millikan (oil drop experiment)
General
✓✗The incorrect set of quantum numbers from the following is
- n = 5, l = 3, ml = −3, −2, −1, 0, +1, +2, +3, ms = +1/2
- n = 4, l = 3, ml = −3, −2, −1, 0, +1, +2, +3, ms = −1/2
- n = 5, l = 2, ml = −2, −1, +1, +2, ms = +1/2
- n = 4, l = 2, ml = −2, −1, 0, +1, +2, ms = −1/2
General
✓✗The maximum number of electrons with n = 4 and ms = +1/2 is
- 4
- 16
- 8
- 32
General
✓✗The minimum energy required to remove an electron from a metal surface is called its
- work function
- ionisation potential
- threshold frequency
- stopping potential
General
✓✗Which of the following statements about the 1s and 2s orbitals of hydrogen is correct?
- 1s has a node at the nucleus
- Both are spherical, but 2s has one radial node
- Both have one radial node
- 2s is smaller than 1s