MCQs on Periodic Classification of Elements

The periodic table is a systematic arrangement of all the known chemical elements. In the modern periodic table, the atoms are arranged with the increasing atomic number. There is a certain observable periodic trend of physical and chemical properties of elements in a group from top to bottom and in a period when we move from left to right. The periodic classification helps in determining the relationship between elements and predicts the chemical properties and behaviour of a newly discovered element.

1. Find the successive elements of the periodic table with ionisation energies, 2372, 520 and 890 kJ per mol respectively

(a) Li, Be, B

(b) H, He, Li

(c) B, C, N

(d) He, Li, Be

Answer: (d)

2. In the modern periodic table, the number of period of the element is the same as

(a) principal quantum number

(b) atomic number

(c) azimuthal quantum number

(d) atomic mass

Answer: (a)

3. The correct order for the size of I, I⁺, I^– is

(a) I > I^– > I⁺

(b) I > I⁺ > I^–

(c) I^– > I > I⁺

(d) I⁺ > I^– > I

Answer: (c)

4. For the same value of n, the penetration power of orbital follows the order

(a) s = p = d = f

(b) p > s > d > f

(c) f < d < p < s

(d) s < p < d < f

Answer: (c)

5. Which of the reactions will need the maximum amount of energy?

(a) Na → Na⁺ + e^–

(b) Ca⁺ → Ca⁺⁺ + e^–

(c) K⁺ → K^{+ +}+ e^–

(d) C²⁺ → C³⁺ + e^–

Answer: (c)

6. Which of the following statements is incorrect?

(a) I.E.₁ of O is lower than that of N but I.E.₂ O is higher than that of N

(b) The enthalpy of N to gain an electron is almost zero but of P is 74.3 kJ mol^-1

(c) isoelectronic ions belong to the same period

(d) The covalent radius of iodine is less than its Van der Waal’s radius

Answer: (c)

7. The correct order of electronegativity is

(a) Cl > F > O > Br

(b) F > O > Cl > Br

(c) F > Cl > Br > O

(d) O > F > Cl > Br

Answer: (b)

8. Two different beakers contain M₁-O-H, and M₂-O-H solutions separately. Find the nature of the two solutions if the electronegativity of M₁ = 3.4, M₂ = 1.2, O = 3.5, H = 2.1

(a) acidic, acidic

(b) basic, acidic

(c) basic, basic

(d) acidic, basic

Answer: (d)

9. Which one is the most acidic among these?

(a) MgO

(b) CaO

(c) Al₂O₃

(d) Na₂O

Answer: (c)

10. Which one will have the highest 2nd ionisation energy?

(a) 1s² 2s² 2p⁶ 3s¹

(b) 1s² 2s² 2p⁴

(c) 1s² 2s² 2p⁶

(d) 1s² 2s² 2p⁶ 3s²

Answer: (a)

Recommended Video:

Periodic Properties Class 11 Chemistry | NEET Class 11 Chemistry | NEET 2022 Exam Preparation