MCQs on Periodic Classification of Elements

MCQs on Periodic Classification of Elements

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)