Chapter-3: Classification of Elements and Periodicity in Properties

1. Which of the following has the highest boiling point?

  • Ne
  • Xe
  • Ar
  • Kr.
Answer
Xe

2. Which of the following has the maximum number of unpaired electrons?

  • Mg2+
  • Ti3+
  • V3+
  • Fe2+
Answer
Fe2+

3. Representative elements are those which belong to

  • p and d – Block
  • s and d – Block
  • s and p – Block
  • s and f – Block
Answer
s and p – Block

4. The most electronegative element of the periodic table is

  • Iodine
  • Sulphur
  • Oxygen
  • Fluorine.
Answer
Fluorine.

5. In the periodic table, the element with atomic number 16 will be placed in the group

  • Third
  • Fourth
  • Fifth
  • Sixth
Answer
Sixth

6. In the third period of the Periodic Table the element having smallest size is

  • Na
  • Ar
  • Cl
  • Si
Answer
Ar

7. Which pair of elements belongs to same group?

  • Elements with atomic no. 17 and 38
  • Elements with atomic no. 20 and 40
  • Elements with atomic no. 17 and 53
  • Elements with atomic no. 11 and 33
Answer
Elements with atomic no. 17 and 53

8. The group number, number of valence electrons, and valency of an element with the atomic number 15, respectively, are:

  • 16, 5 and 2
  • 15, 5 and 3
  • 16, 6 and 3
  • 15, 6 and 2
Answer
15, 5 and 3

9. The element with highest second ionization energy is

  • Cl
  • S
  • Na
  • Mg
Answer
Na

10. The chemistry of lithium is very similar to that of magnesium even though they are placed in different groups. Its reason is:

  • Both are found together in nature
  • Both have nearly the same size
  • Both have similar electronic configuration
  • The ratio of their charge and size is nearly the same
Answer
The ratio of their charge and size is nearly the same

11. Which of the following oxides is amphoteric in character?

  • SnO2
  • CO2
  • SiO2
  • CaO
Answer
SnO2

12. According to the periodic law of elements, the variation in properties of elements is related to their

  • nuclear neutron
  • atomic masses
  • nuclear masses
  • atomic numbers
Answer
atomic numbers

13. The d-block elements consists mostly of

  • Monovalent metals
  • All non-metals
  • Elements which generally form stoichiometric metal oxide
  • Many metals with catalytic properties
Answer
Many metals with catalytic properties

14. The group number, number of valence electrons, and valency of an element with the atomic number 15, respectively, are:

  • 16, 5 and 2
  • 15, 5 and 3
  • 16, 6 and 3
  • 15, 6 and 2
Answer
15, 5 and 3

15. Which of the following properties generally decreases along a period?

  • Ionization Energy
  • Metallic Character
  • Electron Affinity
  • Valency.
Answer
Metallic Character