Question

Statement – 1: First ionization energy of Ge is greater than Si.
Statement – 2: First ionization energy of Pb is greater than Sn.

• A. Statement – 1 is true, Statement – 2 is false
  (2) Statement – 1 and Statement – 2 are false
  (3) Both the Statements are true
  (4) Statement – 1 is false, Statement – 2 is true
• B. Statement – 1 and Statement – 2 are false
• C. Both the Statements are true
• D. Statement – 1 is false, Statement – 2 is true

Hint:

Ionization energy generally increases across a period and decreases down a group due to atomic size and shielding effects. However, there are exceptions due to electron configurations.

Answer 1

The Correct Option is A

- Statement 1: First ionization energy of Ge is greater than Si. In general, ionization energy increases across a period from left to right due to increasing nuclear charge and decreasing atomic radius. However, there are exceptions in certain cases due to subshell configurations. Ge (Germanium) is in the same group as Si (Silicon), but Ge is positioned below Si in the periodic table. As we move down a group, ionization energy tends to decrease due to the increase in atomic size and shielding effect. Thus, the first ionization energy of Si is actually higher than that of Ge. Therefore, Statement 1 is false. - Statement 2: First ionization energy of Pb is greater than Sn. Pb (Lead) and Sn (Tin) belong to Group 14, but Pb is below Sn in the periodic table. As a result, Pb has more electron shells than Sn, leading to a larger atomic size and increased shielding effect, which results in a lower ionization energy. Hence, Statement 2 is false. Therefore, both the statements are false, so the correct answer is: Statement – 1 is true, Statement – 2 is false.