Classification of Elements and Periodicity in Properties Mock Test – Class 11 Chemistry

1. The order of increasing reactivity among the alkali metals , , and is

2. The second period contains elements because the available subshells in that period are

3. The table gives four possible pairs.

The row that needs correction is

4. A configuration note mentions filling along with outer electrons. The safest classification is

5. Transition elements are generally associated with the -block because their differentiating electron enters the

6. A group element commonly forms compounds in which its oxidation state is

7. The later discovery of noble gases did not seriously disturb Mendeleev's table because they could be placed

8. Match the predicted names in Column I with the elements later associated with them.

9. Assertion: The third period contains elements, not .
Reason: In the filling order, starts after , so period ends with .

10. The table gives four statements about -block elements. Select the statement that best fits the transition-element idea.

11. The table shows possible oxidation-state patterns for some -block groups.

The row that needs correction is

12. A claim says, “Valency and number of valence electrons are always identical.” The best evaluation is that the claim is

13. Consider the statements about the early need for classifying elements.
I. Classification was needed because the number of known elements increased.
II. Useful classification should be based only on alphabetical order.
III. Similarities in properties can help form element families.
IV. Unsystematic grouping may fail to show deeper periodic patterns.
The supported set is

14. The graph description below is for electron gain enthalpy.

The most suitable reason for the noble-gas change is that

15. A student says, “Electronegativity is just electron gain enthalpy with a different name.” The best correction is that electronegativity is

16. A non-bonded distance between two neighbouring atoms of the same noble gas in the solid state is . The van der Waals radius is closest to

17. A period element has oxide , hydride , and a common negative oxidation state in its hydride. The element most likely belongs to

18. The reactivity of halogens as non-metals is closely connected with their tendency to

19. A second-period element differs from its third-period group member partly because the second-period valence shell contains only

20. Mendeleev could correct some doubtful atomic masses because

21. The row in the table that best represents a valid modern-periodic-law link is

22. A claim states, “A negative ion is always smaller than a positive ion because the negative sign pulls electrons inward.” The best correction is that

23. An element lies to the right of silicon in period and forms a covalent oxide that reacts with water to form an acid. This observation supports the idea that

24. The row in the table that needs correction is

25. Assertion: The maximum covalency of oxygen is lower than that of sulfur in common basic-level periodicity discussions.
Reason: Oxygen is a second-period element without valence -orbitals, while sulfur is a third-period element.

26. A graph is described below.

The downward slope is best explained by

27. A short note says: “Element lies near the left side of a period, while element lies near the right side before the noble gas. In a bond, pulls the shared electron pair more strongly.” The note is mainly using

28. The long-form modern periodic table contains

29. The most integrated explanation for periodic trends in size, ionization enthalpy, electronegativity, and metallic character is that they are all influenced by

30. Assertion: Actinoids are generally treated with awareness that many of them are radioactive.
Reason: Actinoids belong to the period inner-transition series associated mainly with filling.

31. The table shows element-type locations. Select the row with the best description.

32. Magnesium has a higher first ionization enthalpy than sodium because magnesium has

33. A short note says: “Element belongs to group . It forms a hydride and an oxide in which can show .” The note most strongly illustrates that

34. For an atom with electronic distribution , the valence shell is the shell containing

35. Same-shell electrons shield one another poorly compared with inner-shell electrons. This fact helps explain why, across a period,

36. A claim says, “The block of an element is always decided only by the highest principal quantum number .” This claim fails because

37. A pair of elements has outer configurations and . The best conclusion is that they

38. A correct comparison of first electron gain enthalpy is

39. Moving from to across period , the broad change in character is

40. The row that best distinguishes a periodic pattern from a non-periodic listing is

41. Select the pair that is matched with the correct role in periodic-table vocabulary.

42. In Mendeleev-style classification, oxide and hydride formulae were useful because they gave evidence about

43. Down group , metallic character generally increases because

44. A graph is described below.

For the same movement down the group, the metallic reactivity curve would generally

45. A student compares , , and and expects a perfectly smooth increase in first ionization enthalpy. The best correction is that

46. Assertion: Mendeleev's decision to leave gaps increased confidence in his table.
Reason: The properties predicted for some missing elements were later found to be close to the observed properties of discovered elements.

47. The prefix in names such as eka-aluminium and eka-silicon was useful because it indicated

48. The oxidation state of phosphorus in , taking chlorine as , is

49. A classification note says: “When increases, electrons are added according to definite shell and subshell patterns. After certain intervals, similar outer configurations appear again.” This note explains

50. Use the arrangement described below: a diagonal zig-zag line separates a large metallic region on the left and centre from a non-metallic region toward the upper right. Elements close to this line include , , , , , and . These elements are best described as