TRB PG Assistant - Modern periodic law and periodicity in properties Online Test (MCQ Quiz)

1. Who is credited with developing the first modern periodic table based on atomic number?

A) Dmitri Mendeleev B) Antoine Lavoisier C) Henry Moseley D) Lothar Meyer

2. The modern periodic law states that the physical and chemical properties of elements are periodic functions of their:

A) Atomic mass B) Atomic number C) Number of neutrons D) Electronegativity

3. In the modern periodic table, periods correspond to:

A) The number of valence electrons B) The principal quantum number (n) C) The number of protons D) The number of neutrons

4. Groups in the modern periodic table represent elements with the same:

A) Principal quantum number B) Number of electron shells C) Number of valence electrons D) Atomic mass

5. Which of the following properties generally decreases across a period from left to right?

A) Ionization enthalpy B) Electronegativity C) Atomic radius D) Electron gain enthalpy

6. Which property generally increases down a group in the periodic table?

A) Atomic radius B) Ionization enthalpy C) Electronegativity D) Electron affinity

7. The first ionization enthalpy is the energy required to remove the most loosely bound electron from:

A) A neutral gaseous atom B) A gaseous anion C) A gaseous cation D) A solid atom

8. Which element has the highest first ionization enthalpy?

A) Helium B) Neon C) Argon D) Krypton

9. Which element has the lowest first ionization enthalpy?

A) Fluorine B) Lithium C) Cesium D) Oxygen

10. Atomic radius generally decreases across a period due to:

A) Increase in nuclear charge and shielding effect B) Decrease in nuclear charge and shielding effect C) Increase in nuclear charge and constant shielding effect D) Decrease in nuclear charge and increase in shielding effect

11. Down a group, atomic radius increases primarily because of:

A) Increase in nuclear charge B) Increase in the number of electron shells C) Decrease in shielding effect D) Decrease in valence electrons

12. Electronegativity is the tendency of an atom to attract:

A) Protons towards its nucleus B) Electrons towards its nucleus in a chemical bond C) Neutrons towards its nucleus D) Positively charged ions

13. Which element is the most electronegative?

A) Chlorine B) Oxygen C) Fluorine D) Bromine

14. Which element is the least electronegative among halogens?

A) Fluorine B) Chlorine C) Bromine D) Iodine

15. Electron gain enthalpy is the energy change when an electron is added to:

A) A neutral gaseous atom B) A gaseous cation C) A gaseous anion D) A solid atom

16. Which element has the most negative electron gain enthalpy?

A) Sodium B) Chlorine C) Argon D) Potassium

17. Elements with a negative electron gain enthalpy tend to:

A) Lose electrons easily B) Gain electrons easily C) Form positive ions D) Be noble gases

18. Metallic character generally decreases across a period because:

A) Ionization enthalpy decreases B) Electronegativity decreases C) Nuclear charge increases, making it harder to lose electrons D) Atomic radius increases

19. Non-metallic character generally increases down a group because:

A) Atomic radius decreases B) Ionization enthalpy increases C) Electronegativity decreases, making it harder to attract electrons D) Number of valence electrons increases

20. Oxidation state refers to the hypothetical charge that an atom would have if:

A) It gained all its valence electrons B) It lost all its valence electrons C) All its bonds were to atoms of the same element D) All its bonds were to atoms of greater electronegativity and the electrons were assigned to the more electronegative atom

21. Which of the following is a metalloid?

A) Iron B) Copper C) Silicon D) Sulfur

22. The alkali metals (Group 1) are characterized by:

A) High ionization enthalpy and low reactivity B) Low ionization enthalpy and high reactivity C) Full valence electron shells D) Tendency to form negative ions

23. The halogens (Group 17) are characterized by:

A) High ionization enthalpy and low reactivity B) Tendency to lose one electron to form +1 ions C) High electronegativity and tendency to gain one electron D) Being noble gases

24. Noble gases (Group 18) are characterized by:

A) High reactivity and tendency to gain electrons B) Low ionization enthalpy and tendency to lose electrons C) Full valence electron shells and very low reactivity D) Being highly electronegative

25. The blocking of d-orbitals in transition metals affects which property significantly?

A) Atomic radius B) Ionization enthalpy C) Color of compounds D) Melting point

26. Which of the following elements exhibits the most pronounced metallic character?

A) Magnesium B) Aluminum C) Sodium D) Potassium

27. Lanthanides and actinides are collectively known as:

A) Alkali metals B) Transition metals C) Inner transition metals D) Halogens

28. The element with the electronic configuration $1s^2 2s^2 2p^6 3s^2 3p^6 4s^1$ belongs to which group?

A) Group 1 B) Group 2 C) Group 11 D) Group 17

29. The element with the electronic configuration $1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^2 4p^5$ belongs to which group?

A) Group 16 B) Group 17 C) Group 18 D) Group 1

30. Which of the following is an exception to the general trend in ionization enthalpy across a period?

A) Nitrogen ($Z=7$) and Oxygen ($Z=8$) B) Boron ($Z=5$) and Carbon ($Z=6$) C) Lithium ($Z=3$) and Beryllium ($Z=4$) D) Neon ($Z=10$) and Fluorine ($Z=9$)

31. The deviation from the expected trend in electron gain enthalpy for elements like Nitrogen is due to:

A) Half-filled p-orbitals B) Fully-filled s-orbitals C) Increased nuclear charge D) Increased electron-electron repulsion in a smaller atom

32. The atomic radii of the elements in the second period show a general decrease from Li to Ne. Which pair of elements deviates from this trend?

A) Be and B B) B and C C) N and O D) F and Ne

33. The ionization enthalpy generally increases across a period. Which element is an exception to this trend and has a lower value than the preceding element?

A) Carbon B) Nitrogen C) Oxygen D) Fluorine

34. Which of the following ions is isoelectronic with Neon ($Ne^{10+}$)?

A) Sodium ($Na^+$) B) Magnesium ($Mg^{2+}$) C) Aluminum ($Al^{3+}$) D) All of the above

35. The ionic radius of $F^-$ is larger than that of $O^{2-}$ because:

A) $F^-$ has more protons B) $O^{2-}$ has more electrons C) $F^-$ has a higher ratio of electrons to protons D) $O^{2-}$ has a lower ratio of electrons to protons

36. Which of the following statements about periodic trends is INCORRECT?

A) Atomic radius decreases across a period. B) Ionization enthalpy increases down a group. C) Electronegativity increases across a period. D) Metallic character decreases down a group.

37. The element with electronic configuration $[Ar] 3d^5 4s^1$ belongs to:

A) Group 1 B) Group 6 C) Group 11 D) Group 16

38. Which of the following pairs of elements have similar chemical properties?

A) Li and Na B) Li and Mg C) Na and Cl D) K and Ca

39. The element that is diamagnetic in its common oxidation state is:

A) Ti ($Z=22$) B) V ($Z=23$) C) Sc ($Z=21$) D) Fe ($Z=26$)

40. The element that exhibits the highest oxidation state is:

A) Manganese (Mn) B) Chromium (Cr) C) Vanadium (V) D) Iron (Fe)

41. Which of the following oxides is amphoteric?

A) $Na_2O$ B) $Al_2O_3$ C) $SO_2$ D) $CO_2$

42. The trend in the basicity of oxides across a period is:

A) Increases B) Decreases C) Remains constant D) First increases then decreases

43. The trend in the basicity of oxides down a group is:

A) Increases B) Decreases C) Remains constant D) First decreases then increases

44. Which property is most affected by the shielding of d-electrons in transition metals?

A) Melting point B) Density C) Ionization enthalpy D) Catalytic activity

45. The ionization enthalpies of transition metals show:

A) A sharp increase B) A gradual increase C) A significant decrease D) No clear trend

46. Which of the following is a characteristic property of transition metals?

A) Formation of colorless compounds B) Variable oxidation states C) Low melting points D) Tendency to form acidic oxides

47. The element with the electronic configuration $[Kr] 4d^{10} 5s^2$ belongs to:

A) Group 10 B) Group 11 C) Group 12 D) Group 13

48. Which of the following elements has the largest atomic radius?

A) Li B) Be C) B D) C

49. Which of the following is a consequence of the lanthanide contraction?

A) Increase in atomic radii of elements in the third transition series B) Decrease in ionization enthalpy of elements in the third transition series C) Similar chemical properties between second and third transition series elements D) Higher reactivity of third transition series elements

50. The highest ionization enthalpy for the second period elements is observed for:

A) Lithium B) Carbon C) Fluorine D) Neon

Modern periodic law and periodicity in properties - Online Test

Test Results