Akaki Adventist School

Work Sheet for Grade 12 Chemistry

From Grade 11Chemistry Unit Two
Atomic Structure and the Periodic table
Atom, Atomic theory, Dalton’s atomic theory (DAT), limitation of DAT, Modern atomic
theory (MAT), Postulates of modern atomic theory, How the modern atomic theory
explains the mass law? Discovery of the electron, Radioactivity, discovery of Nucleus,
Discovery of nucleus, Discovery of Neutron, Makeup of the nucleus, Atomic mass,
isotopes, Electromagnetic radiation, Wave length (λ), Frequency (ν), Amplitude(A),
Speed(c), Electromagnetic spectrum, Quantum theory, photon, Photoelectric effect,
work function, Atomic spectra, Bohr model of hydrogen atom, Dual nature of light, The
quantum mechanical model of the atom, Heisenberg’s uncertainty principle, Quantum
numbers, Shapes of atomic orbitals, Electron configuration and orbital diagram,
Modern periodic table, Classification of the elements, Periodic properties

I. CHOOSE THE BEST ANSWER FROM THE GIVEN ALTERNATIVES

1. Of the following, _________ has the maximum frequency.
A. UV Rays B. Gamma Rays C. Microwaves D. Radio Waves
2. Wavelength and frequency are related as: (c = speed of light)
A. c = wavelength / frequency B. frequency = wavelength / c
C. wavelength = c * frequency D. c = wavelength * frequency
3. Electromagnetic waves can be visualized as a
A. Sine wave B. Cosine wave
C. Tangential wave D. None of the mentioned
4. Which of the following is used for chest and dental scans?
A. Hard X-rays B. Soft X-rays C. Radio waves D. Infrared Rays
5. Mass less particle containing a certain amount of energy is called
A. Photon B. Shell C. Electron D. None of the mentioned
6. What do you mean by a chromatic light?
A. Chromatic light B. Monochromatic light
C. Infrared light D. Invisible light
7. Which of the following is determined by Millikan’s oil drop experiment?
A. Velocity of electron B. Mass of electron
C. Charge on electron D. ratio of an electron
8. From three types of particles of radioactive, which of the following is
characterized by Rutherford?
A. γ- rays B. β- D
9. β radiation is
A. Positively charged particles B. Negatively charged particle
C. Characterized by energy D. Helium ion
10. Which of the following pair of elements do have the same number of
neutron?
A 147N & 168O B. 2311Na & 2412Mg C. 73Li & 94Be D. 3216S & 3517Cl

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11. Which of the following is true about a mono atomic ion that has 20 protons
and +2 charge?
A. has 16 Proton B. has 18 neutron
C. The element is Ar +2 D has iso electronic configuration with Ar
12. Natural copper consists of 63Cu and 65Cu. What is the natural abundance
of 63Cu if the average mass of isotope is 63.5?
A.75% B.25% C.50% D.33%
13. What is the difference between chlorine 35 & chlorine 37?
A. Chlorine 37 has two more proton than chlorine 35
B. Chlorine 37 has two more neutron than chlorine 35
C. Chlorine 37 has two more electron than chlorine 35
D. Chlorine 37 has equal numbers of neutrons with chlorine 35
14. What is the chemical symbol of the ion that contains 19 protons, 18
electrons and 20 neutrons?
A. 3819K+ B. 4020K+ C. 3919K+ D. 2920K+
15. Which of the following electromagnetic radiation has the longest wave
length?
A. Gamma rays B. Microwaves C. Radio waves D. X-rays
16. Which region of electromagnetic spectrum is capable of including electron
transitions with the greatest energy?
A.IR B. Microwave C.UV D. Visible light
17. Which of the following statement is true?
A. All forms of electromagnetic radiations are visible
B. Radio waves have shorter wave length than visible light
C. UV light has longer wave length than visible light
D. The frequency of radiation increases as wave length decreases
18. Which of the following electromagnetic radiation has the shortest wave
length?
A. X-ray B. Gamma ray C. UV-ray D. Microwave
19. Which of the following electron transition require the smallest energy to be
absorbed by hydrogen atom?
A. From n=1 to n=2 B.From n=2 to n= 3
C. From n=3 to n=4 D. From n=4 to n=5
20. Which of the following transitions will emit maximum energy in the
hydrogen atom?
A. n=2 to n=1 B. n=4 to n=2 C. n=4 to n=3 D. n=3 to n=3
21. For an electron that has quantum numbers n=4 and ml = 0, which of the
following is true?
A. It must have quantum number n=0
B. It must have quantum number l = 0
C. It must have quantum number ms =
D. It may have quantum number l = 0, 1, 2, 3

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22. Which of the following sets of quantum numbers is not allowed in the
hydrogen atom?
n l ml
A. 2 1 1
B. 1 0 0
C. 8 7 -6
D. 2 0 2
23. What are the possible values of the azimuthal quantum number for an
electron in the 4f sub shell?
A. 0, 1, 2, 3 B. 1, 2, 3 C. 3 D. 4
24. How many electrons can fit in to the orbital that comprise the 3rd quantum
shell (n=3)?
A. 2 B. 8 C. 9 D. 18
25. What is the maximum number of electrons in an atom that can have the
quantum numbers n=5, ml = +1?
A. 8 B. 16 C. 32 D. 52
26. How many orbitals are in an atomic sub level with l = 3?
A. 3 B. 5 C. 7 D. 9
27. Which of the following quantum numbers (is) are related to the size and
energy of an electron in a hydrogen atom?
A. n B. n and l C. n, l and ml D. n, l, ml, and ms
28. How many orbitals are there in an atom with n=4?
A. 2 B. 8 C. 16 D. 25
29. The maximum number of electrons in p-orbitals with n = 6, ml = 0 is
A. 2 B. 6 C. 16 D. 14
30. For which of the following elements is Hund’s rule used in writing the
electronic configuration?
A. 6C B. 3Li C. 5B D. 4Be
31. What is the electronic configuration of N ? 3-

A. 1s22s2 B. 1s2 2s2 2p3 C. 1s22s22p6 D.1s22s22p5

32. Which element is corresponds to the electronic configuration of [Ne]
3s23p1?
A. 12Mg B. 13Al C. 14Si D. 31Ga
33. Which of the following is correct electronic configuration of 28Ni?
A. 1s22s22p63s23p64s23d8 B. 1s22s22p63s23p64s13d9
C. 1s22s22p63s23p64s24p65s2 D. 1s22s22p63s23p64s23d64p6
34. A neutral atom x at its ground state has half-filled electron 4f orbital. What
is the atomic number of x?
A. 45 B.71 C. 63 D. 57
35. Which of the following sets of quantum numbers could be those of the last
electron of 42Mo?
A. n=4, l=0, ml=0, ms = + B. n = 5, l=0, ml=0, ms = ±
C. n=4, l=2, ml=-1, ms = + D. n=3, l=2, ml=0, ms = +
36. What is the number of unpaired electrons for 24Cr?
A. 6 B. 5 C. 4 D. 3

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37. An electron has spin quantum numbers ms= + and Magnetic quantum
numbers ml = +1, in which of the following orbitals will not be present?
A. s- Orbitals B. p- Orbitals C. d- Orbitals D. f- Orbitals
38. What size of particles and velocities can one consider in quantum effect?
A. Particle with very large mass and large velocities
B. Particle with large mass and small velocities
C. Particle with very small mass and large velocities
D. Particle with very small mass and small velocities
39. Which of the following atoms in its ground state has the greatest number of
unpaired electrons?
A.13Al B. 14Si C.15P D.16S
40. Which of the following is the correct ground state electronic configuration of
17Cl-1?
A. 1s22s22p63s23p6 B. 1s22s22p63s23p5
C. 1s 2s 2p 3s
2 2 6 1 D.1s22s22p63s13p5
41. How many unpaired electrons are there in the Lewis structure of N3-?
A. 0 B.1 C. 2 D. 3
42. When the atoms 3Li, 4Be, 5B and 11Na are arranged in order of increasing
atomic size, which one is correct?
A. B, Be, Li, Na, B. Na, B, Be, Li C. Li, Be, B, Na D. Be, B, Na, Li
43. Which of the following has the greatest effective nuclear charge?
A. 19K B. 20Ca C. 35Br D. 15P
44. Which group of elements are the most reactive metallic elements?
A. Alkali metal B. Alkali earth metal
C. Transition metal D. Post transitional metals
45. Which alkali earth metal share diagonal relationship with Al?
A. Ba B. B C. Be D. Mg