Q1. The mass of one Avogadro number of helium atom is
(a) 1.00 g
(b) 4.00 g
(c) 8.00 g
(d) 6.02 × 1023 g
Q2. The maximum electron capacity of any orbital is
(a) 2
(b) 6
(c) 14
(d) Cannot be determined unless the principal quantum number is known
Q3. The names of the scientists, Newlands, Mendeleev and Meyer are associated with the development of
(a) Atomic structure
(b) Metallurgy
(c) Periodic table of elements
(d) Discovery of elements
Q4. The nuclear particles that are assumed to hold nucleons together are
(a) Electrons
(b) Positrons
(c) Neutrons
(d) Mesons
Q5. The nucleus of a hydrogen atom consists of
(a) One proton
(b) One proton + two neutrons
(c) One neutron only
(d) One electron only
Q6. A molecule whose electrons are distributed unsymmetrical is said to be
(a) Ionised
(b) Non-ionised
(c) Polar
(d) Non-polar
Q7. Bohr’s theory of fixed orbits contradicts
(a) Coulomb’s law
(b) Planck’s theory
(c) de Broglie relation
(d) Uncertainty principle
Q8. Evidence for the existence of energy level in atom is supplied by
(a) Atomic numbers
(b) Atomic radii
(c) Spectral lines
(d) Mass defects
Q9. For the dumb bell shaped orbital, the value of l is
(a) 3
(b) 1
(c) 0
(d) 2
Q10. Which quantum number cannot have an integral value?
(a) n
(b) l
(c) m
(d) s
Q11. How many orbitals make up any s-sublevel?
(a) 1
(b) 3
(c) 5
(d) 7
Q12. According to Bohr’s theory, an electron in one Bohr stationary orbit can go to a higher stationary orbit
(a) By emission of electromagnetic radiation
(b) Without any absorption or emission of electromagnetic radiation
(c) With absorption of any electromagnetic radiation
(d) With absorption of electromagnetic radiation of a particular frequency
Q13. According to Bohr’s theory of hydrogen atom, the angular momentum of the electron in the fourth orbit is given by
(a) h/2?
(b) 4h/?
(c) h/?
(d) 2h/?
Q14. According to Einstein’s mass-energy relation
(a) E = m^2 c
(b) E = mc
(c) E = mc^2
(d) E = vmc
Q15. According to Heisenberg’s uncertainty principle; it is not possible to determine
(a) The position of the electron accurately
(b) The momentum of the electron accurately
(c) Simultaneously the position and momentum of an electron accurately
(d) None of these
