Dr. AQ Khan School and college, Bahria Town Phase 8, Islamabad
SLO Based Worksheet Chemistry Class XI
Chapter 2: Atomic Structure
Prepared by: Sana Ahsen
Q. Select the correct answer from the following given choices.
1. In the discharge tube when the pressure was reduced to 0.01 torr, and a voltage of 500010000V is applied, certain rays travelled towards anode, these were;
a. Positive rays
b. Cathode rays
c. Neutrons
d. Alpha rays
2. Which of the following produce X-rays upon striking anode, particularly with a large atomic
mass:
a. Electrons
b. Positive rays
c. Cathode rays
d. both (a) and (c)
c. Slow neutrons
d. Neutrino
3. Neutrons with the energy 1.2MeV are called:
a. Projectiles
b. Fast neutrons
4. Neutrons are neutral as indicated by:
a. Charge detector (showed them to be neutral)
b. They are not deflected in electric field
c. They are not deflected in a magnetic field
d. All of the above
5. Highest e/m is obtained by which of the following gas in discharge tube:
a. Helium
b. neon
c. Hydrogen
d. Nitrogen
6. In calculating Bohr’s radius of orbit, centripetal force on an electron is equal to:
a.
b.
c. Fc= P.E
d. Fc =
7. The energy of electron in ground state of hydrogen atom is:
a. -1313.35 kJ/mol
b. -328.32 kJ/mol
d. 2.18 × 10-18 /n2 J
c. 0 kJ/mol
8. The relationship between frequency ν and wavelength λ is
a. ν = c/ λ
b. λ= c ν
c. ν = 2λ
d. ν= cλ2
9. The units of Rydberg’s constant R= 1.09678 × 107 are same as those of:
a. Frequency
b. Energy
c. Wavenumber
d. Charge
10. The energy required to bring an electron from first orbit of hydrogen to infinity is also called:
a. Potential energy
b. Ionization energy c. Electron infinity
d. Energy of first orbit E1
11. The visible emissions in hydrogen spectrum are due to which of the following series:
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a. Lyman series
b. Balmer series
c. Paschen series
d. Pfund series
12. Express energy of the photon 10-25 J in ergs when 1J= 107 ergs
a.10-18 ergs
b. 10-32 J
c. 10-17 J
d. 10-25 J
13. The frequency of the emitted line in X-ray spectrum varies as the square of atomic number of
an element emitting it; √ν =a (Z-b). This statement is called:
a. Coulomb’s law
b. Moseley’s law
c. Bragg’s law
d. Plank’s law
14. The number of electrons in an orbit n is given by:
a. 2n
b. 4n
c. 2n2
d. 4n2
15. d-orbital has up to how many orientations in Magnetic field?
a. Three
b. Five
c. One
d. seven
Give short answers:
1.
2.
3.
4.
5.
6.
Calculate the wave number of limiting line of Balmer series.
Convert the Energy E=1.962× 10-17 J into frequency ν in Hertz and in m-1 and cm-1.
How can you relate the concept of quantized energy with the line spectrum of hydrogen.
Draw the shapes of s, p and f orbitals with respect to orientation in 3 dimensions.
Give a brief account of production of X-rays in cathode ray tube.
How can you relate frequency of X-rays with the atomic number of anode metal? Give
equation.
7. Write down the electronic configuration of :
a. 29Cu
b. 26Fe
c. 22Ti
d. 23V
e. 14Si
8. Explain magnetic quantum (m) number and how is this related to azimuthal quantum number
(l).
9. Explain, how does the discovery of positive rays led to the discovery of proton?
10. Explain the significance of (n+l) rule.
11. How much energy is required to make electron jump from n=3 to n=5 in a hydrogen atom.
12. Calculate the expression for when an electron jumps from n1 to n2 in a hydrogen spectrum.
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