Periodic Classification of Elements MCQ Solved Paper for UPSC CDS

1. Which of the following have negative electron affinity?
A. Kr
B. U
C. Y
D. Pb
Answer : A

2. The heaviest element is
A. Cs
B. Na
C. Hg
D. U
Answer : D

3. In the Mendeleef's periodic table properties of the elements are the periodic function of their
A. atomic weight
B. atomic number
C. atomic volume
D. none of these
Answer : A

4. Which of the following atoms is paramagnetic?
A. Zn
B. N
C. Ca
D. Sr
Answer : B

5. The successive ionisation energies of an atom of an element A are:
$900 kJ mol{e}^1$, $1757 kJ mol{e}^{-1}$, $14850 kJ mol{e}^{-1}$ respectively. The element is most likely to be
A. B
B. Be
C. F
D. Ba
Answer : B

6. Which of the following is an inert gas?
A. Oxygen
B. Nitrogen
C. Argon
D. Hydrogen
Answer : C

7. Which of the following elements is not liquid at room temperature, i.e., 25°C?
A. Hg
B. Br
C. Cl
D. Cs
Answer : D

8. Which of the following is not an s-block element?
A. Ru
B. Be
C. Fr
D. Rb
Answer : A

9. Which of the following conform both cation and anion?
A. I
B. Cl
C. K
D. F
Answer : A

10. In C, N, O and F the electronegativity
A. decreases from C to F
B. decreases from C to O and then increases to F
C. increases from O to C and then decreases to F
D. increases from C to F
Answer : D

11. Which of the following species have minimum size?
A. $B{r}^{-}$
B. $S^{-2}$
C. $Ne$
D. $K^{+}$
Answer : D

12. The element with no definite place in the periodic table is
A. At
B. H
C. N
D. Pt
Answer : B

13. Which of the following did not find a place in Mendeleef's periodic table?
A. Fr
B. Na
C. Ce
D. CI
Answer : A

14. Which of the following elements have maximum electronegativity?
A. Cl
B. Br
C. F
D. C
Answer : C

15. The lightest metal is
A. Li
B. Pb
C. Na
D. Al
Answer : A

16. Which of the following has maximum electron affinity ?
A. Cl
B. Br
C. I
D. F
Answer : A

17. An atom of an element has electronic configuration $\left(Ar\right) 4s^{2}3d^5$, the element belongs to block
A. s
B. p
C. f
D. d
Answer : D

18. The first atom with maximum number of d-electrons is with atomic number
A. 27
B. 46
C. 36
D. 29
Answer : D

19. The differentiating electron enters in the penultimate energy level in the case of
A. s block ele.
B. p block ele.
C. d block ele.
D. f block ele.
Answer : A

20. A metal may have atomic number
A. 85
B. 32
C. 38
D. 2
Answer : C

21. Which of the following has maximum ionisation energy ?
A. Li
B. Be
C. C
D. B
Answer : B

22. An element A has atomic number 7. It will have properties similar to the element with atomic number
A. 85
B. 57
C. 26
D. 51
Answer : D

23. With the increase in atomic number in a period of the periodic table
A. electron affinity decreases
B. metallic character decreases
C. ionisation energy decreases
D. atomic mass decreases
Answer : B

24. Elements in the same vertical column has same
A. valence shell electronic configuration
B. electronic configuration
C. atomic number of isotopes
D. atomic size
Answer : A

25. Modem Periodic Law was given by
A. Joule
B. Moseley
C. Klechkosky
D. Meyer
Answer : B

26. An element has atomic number 2. It belongs to
A. O group
B. III A group
C. VI group
D. II B group
Answer : A

27. Which of the following have maximum size?
A. $Cl$
B. $N_2$
C. $F$
D. $Ne$
Answer : D

28. Arrange the following set of atoms in the order of increasing atomic radius : F, Cl, C, O
A. F, Cl, O, C
B. C. O, F, Cl
C. O. C, F, Cl
D. F, O, C, Cl
Answer : D

29. Ionisation energy of potassium is $425 kJ mo{l}^{-1}$. The minimum frequency of a photon that can effect the ionisation is
A. $96.5\times {10}^{15}se{c}^{-1}$
B. $1.065\times {10}^{14}se{c}^{-1}$
C. $1.065\times {10}^{12}se{c}^{-1}$
D. $1.065\times {10}^{15}se{c}^{-1}$
Answer : D

30. On moving across a period from left to right the ionisation energy increases because
A. value of principal quantum number increases
B. effective nuclear charge increases
C. atomic size increases
D. nuclear charge increases
Answer : A

31. $O^{2-}$, $F^{F-}$, $N{a}^{+}$ and $M{g}^{2+}$ are isoelectronic, the order of increasing size is
A. $F^{-}<N{a}^{+}{g}^{++}<O^{2-}$
B. $F^{-}<O^{2-}<N{a}^{+}<M{g}^{++}$
C. $M{g}^{++}<F^{-}<N{a}^{+}<O^{2-}$
D. $M{g}^{++}<N{a}^{+}<F^{-}<O^{2-}$
Answer : D

32. Elements whose atoms have incompletely filled penultimate energy levels are known as
A. s-block elements
B. p-block elements
C. d-block elements
D. inert gases
Answer : C

33. Second electron affinity of the elements is always
A. positive
B. negative
C. zero
D. more than first E.A.
Answer : B

34. In a Lother Meyer curve sodium occurs at
A. bottom
B. peak
C. some point on the curve
D. middle of the curve
Answer : B

35. Which of the following has highest ionisation energy?
A. Be
B. Cl
C. Ba
D. N
Answer : D

36. IV Period has.........elements.
A. 18
B. 36
C. 8
D. 9
Answer : A

37. Law of octaves was given by
A. Meyer
B. Mendeleev
C. Moseley
D. Newland
Answer : D

38. Which of the following has minimum ionisation energy
A. Ca
B. In
C. Te
D. Rb
Answer : D

39. Which of the following has the maximum size?
A. $A{l}^{-}$
B. $Ne$
C. $N{a}^{+}$
D. $F^{-}$
Answer : B

40. The general electronic configuration of s-block elements is
A. $n{s}^{1-2}$
B. $n{s}^2{p}^6$
C. $n{s}^1$
D. $n{s}^{0 to2}$
Answer : A

41. Which of the following has minimum ionisation energy?
A. F
B. Cl
C. Br
D. I
Answer : D

42. Elements whose atoms have incompletely filled penultimate and anti-penultimate energy levels are known as
A. Inner Transition elements
B. Representative elements
C. Inert elements
D. Noble gases
Answer : A

43. Ionisation energy is the amount of energy required to remove
A. the most loosely bound electron from an isolated gaseous atom
B. an electron from an atom of an element
C. an electron from an isolated gaseous atom
D. an electron from covalently bonded atom in a molecule
Answer : A

44. Arrange the following set of atoms in the increasing order of electron affinity: F, Sr, Ge, Se
A. Ge, Se, Sr. F
B. Se, Ge. Sr. F
C. Sr, Ge. Se. F
D. F, Sr, Ge. Se
Answer : C

45. 3.Atomic number of an element X is 34, it belongs to
A. IV period, VIA group
B. IV period, IIA group
C. V period, III B group
D. IV period, VII A group
Answer : A

46. The pair of elements that exhibit diagonal relationship is
A. Li-Mg
B. Al-Na
C. Ne-Ar
D. Si-P
Answer : A

47. The smallest ion amongst the following
A. $S{i}^{+++1}$
B. $K^{+}$
C. $A{t}^{1+1}$
D. $M{g}^{+1}$
Answer : A

48. In the periodic table on moving from left to right across a period, the metallic character of elements
A. increases
B. decreases
C. increases and decreases
D. remains the same
Answer : B

49. Which of the following has maximum ionisation energy?
A. Li
B. Ba
C. Cl
D. Be
Answer : D

50. Lother Meyer plotted a graph of
A. Atomic volume versus atomic number
B. Atomic radii versus atomic weight
C. Atomic weight versus mass number
D. Atomic volume versus atomic weight
Answer : D