**Periodic Table and Periodicity of Properties MCQs**
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#### **Easy (30%)**
1. **Who introduced the concept of triads in the periodic classification of elements?**
a) Mendeleev
b) Newlands
c) Dobereiner
d) Lavoisier
2. **In Newlands' Law of Octaves, every ___ element showed similarity in properties.**
a) Second
b) Fourth
c) Eighth
d) Tenth
3. **Which scientist is credited with arranging elements in increasing order of atomic mass?**
a) Rutherford
b) Dalton
c) Mendeleev
d) Bohr
4. **The modern periodic law states that the properties of elements are a periodic function of their ___.**
a) Atomic number
b) Atomic mass
c) Molar mass
d) Density
5. **In the periodic table, each horizontal row is called a:**
a) Group
b) Period
c) Block
d) Family
6. **How many periods are there in the modern periodic table?**
a) 5
b) 6
c) 7
d) 8
7. **Which of the following elements belongs to Group 1?**
a) Oxygen
b) Sodium
c) Chlorine
d) Calcium
8. **What is the term for the energy required to remove an electron from an atom?**
a) Shielding effect
b) Ionization energy
c) Electron affinity
d) Electronegativity
9. **Which element has the highest electronegativity?**
a) Fluorine
b) Oxygen
c) Hydrogen
d) Carbon
10. **What is the atomic number of the first element in Period 3?**
a) 1
b) 11
c) 12
d) 13
11. **In which period does Potassium (K) lie?**
a) 1
b) 2
c) 4
d) 6
12. **Groups in the periodic table are arranged:**
a) Vertically
b) Horizontally
c) Diagonally
d) Randomly
13. **Electron affinity is the energy change when an electron is:**
a) Removed from an atom
b) Added to an atom
c) Removed from a molecule
d) Added to a molecule
14. **Which of the following has the smallest atomic radius?**
a) Sodium
b) Magnesium
c) Chlorine
d) Aluminum
15. **What does the shielding effect refer to?**
a) Increase in nuclear charge
b) Decrease in atomic size
c) Decrease in the force between nucleus and outer electrons
d) Increase in electron affinity
16. **Mendeleev's periodic table was arranged according to:**
a) Atomic number
b) Atomic mass
c) Valency
d) Electron configuration
17. **How many elements are in Period 2 of the periodic table?**
a) 8
b) 18
c) 6
d) 10
18. **What is another name for Group 17 elements?**
a) Alkali metals
b) Alkaline earth metals
c) Halogens
d) Noble gases
19. **Which of the following is a characteristic of noble gases?**
a) Highly reactive
b) Low melting points
c) Complete outer electron shell
d) High electronegativity
20. **Which element has the highest ionization energy in Period 2?**
a) Lithium
b) Boron
c) Nitrogen
d) Neon
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#### **Moderate (40%)**
21. **Elements in the same ___ have similar chemical properties.**
a) Period
b) Group
c) Block
d) Energy level
22. **Which of the following increases as we move from left to right across a period?**
a) Atomic radius
b) Ionization energy
c) Metallic character
d) Atomic mass
23. **Which of the following groups contains the alkali metals?**
a) Group 1
b) Group 2
c) Group 15
d) Group 17
24. **How many elements are present in Group 18?**
a) 5
b) 6
c) 7
d) 8
25. **What is the term for the attraction an atom has for electrons in a chemical bond?**
a) Electron affinity
b) Ionization energy
c) Electronegativity
d) Atomic radius
26. **Which period contains both metals and nonmetals?**
a) Period 1
b) Period 2
c) Period 7
d) Period 5
27. **Which of these elements has the largest atomic radius in its period?**
a) Lithium
b) Carbon
c) Nitrogen
d) Neon
28. **Elements in a group generally have the same:**
a) Number of protons
b) Atomic mass
c) Electron configuration
d) Number of valence electrons
29. **The first ionization energy tends to ___ as we move down a group.**
a) Increase
b) Decrease
c) Remain constant
d) Fluctuate
30. **Which of these elements has the highest electron affinity?**
a) Carbon
b) Fluorine
c) Magnesium
d) Oxygen
31. **Ionization energy generally increases across a period because:**
a) Atomic radius decreases
b) Atomic number decreases
c) Electron affinity decreases
d) Shielding effect increases
32. **In the periodic table, elements are arranged in order of increasing:**
a) Atomic number
b) Atomic mass
c) Density
d) Electron affinity
33. **Which group is known as the noble gases?**
a) Group 16
b) Group 17
c) Group 18
d) Group 15
34. **Which has the smallest ionization energy?**
a) Helium
b) Hydrogen
c) Francium
d) Lithium
35. **The shielding effect is more pronounced in:**
a) Smaller atoms
b) Larger atoms
c) Nonmetals
d) Transition metals
36. **The atomic radius of an element depends upon the:**
a) Number of neutrons
b) Nuclear charge
c) Position in a group
d) Both b and c
37. **What happens to the atomic radius as we move down a group?**
a) Increases
b) Decreases
c) Remains the same
d) Varies irregularly
38. **Which element has a greater shielding effect?**
a) Lithium
b) Fluorine
c) Sodium
d) Neon
39. **What is the trend in electronegativity as we go from top to bottom within a group?**
a) Increases
b) Decreases
c) Remains constant
d) No trend
40. **The energy change when an electron is added to a neutral atom is known as:**
a) Ionization energy
b) Electron affinity
c) Electronegativity
d) Shielding effect
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#### **Tough (30%)**
41. **In which group do elements have an oxidation state of +1?**
a) Group 17
b) Group 2
c) Group 1
d) Group 15
42. **Which element in Period 3 has the highest ionization energy?**
a) Sodium
b) Magnesium
c) Chlorine
d) Argon
43. **As we move across a period, atomic size generally decreases due to:**
a) Increased shielding effect
b) Decreased nuclear charge
c) Increased nuclear charge
d) Increased number of energy levels
44. **Why does ionization energy decrease down a group?**
a) Increased shielding effect
b) Increased atomic size
c) Both a and b
d) None of the above
45. **Which of the following elements has the highest electron affinity?**
a) Fluorine
b) Chlorine
c) Bromine
d) Iodine
46. **How does atomic radius change within a period from left to right?**
a) Increases
b) Decreases
c) Remains constant
d) First decreases, then increases
47. **Which of the following has the lowest electronegativity?**
a) Oxygen
b) Nitrogen
c) Fluorine
d) Lithium
48. **The energy needed to remove an electron from an atom in the gaseous state is called:**
a) Electron affinity
b) Ionization energy
c) Electronegativity
d) Shielding effect
49. **Which property shows the least change in a group as compared to a period?**
a) Ionization energy
b) Electronegativity
c) Atomic radius
d) Shielding effect
50. **Which of the following has the smallest atomic radius?**
a) Lithium
b) Boron
c) Carbon
d) Neon
51. **Noble gases are unreactive because they:**
a) Have high ionization energies
b) Have high electron affinities
c) Have complete outer shells
d) Are monatomic
52. **Which element has the highest first ionization energy?**
a) Hydrogen
b) Helium
c) Neon
d) Oxygen
53. **As atomic number increases within a group, electronegativity generally:**
a) Increases
b) Decreases
c) Remains constant
d) Doubles
54. **The ionization energy of elements ___ from left to right across a period.**
a) Increases
b) Decreases
c) Remains constant
d) Decreases, then increases
55. **Electron affinity is highest in elements in:**
a) Group 1
b) Group 2
c) Group 17
d) Group 18
56. **Which factor most affects the ionization energy of an atom?**
a) Shielding effect
b) Number of protons
c) Electron configuration
d) Number of neutrons
57. **Electron affinity values are generally highest in which type of elements?**
a) Alkali metals
b) Alkaline earth metals
c) Halogens
d) Noble gases
58. **Which of the following explains why alkali metals have low ionization energies?**
a) Small atomic size
b) High nuclear charge
c) Large atomic size
d) Strong shielding effect
59. **Which element is in Group 15, Period 3?**
a) Nitrogen
b) Phosphorus
c) Sulfur
d) Chlorine
60. **Ionization energy is least in elements of which group?**
a) Group 1
b) Group 2
c) Group 16
d) Group 17
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### **Answers**
1. c) Dobereiner
2. c) Eighth
3. c) Mendeleev
4. a) Atomic number
5. b) Period
6. c) 7
7. b) Sodium
8. b) Ionization energy
9. a) Fluorine
10. b) 11
11. c) 4
12. a) Vertically
13. b) Added to an atom
14. c) Chlorine
15. c) Decrease in the force between nucleus and outer electrons
16. b) Atomic mass
17. a) 8
18. c) Halogens
19. c) Complete outer electron shell
20. d) Neon
21. b) Group
22. b) Ionization energy
23. a) Group 1
24. d) 8
25. c) Electronegativity
26. b) Period 2
27. a) Lithium
28. d) Number of valence electrons
29. b) Decrease
30. b) Fluorine
31. a) Atomic radius decreases
32. a) Atomic number
33. c) Group 18
34. c) Francium
35. b) Larger atoms
36. d) Both b and c
37. a) Increases
38. c) Sodium
39. b) Decreases
40. b) Electron affinity
41. c) Group 1
42. d) Argon
43. c) Increased nuclear charge
44. c) Both a and b
45. a) Fluorine
46. b) Decreases
47. d) Lithium
48. b) Ionization energy
49. d) Shielding effect
50. d) Neon
51. c) Have complete outer shells
52. b) Helium
53. b) Decreases
54. a) Increases
55. c) Group 17
56. b) Number of protons
57. c) Halogens
58. c) Large atomic size
59. b) Phosphorus
60. a) Group 1
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