Which of the following is true about the general trend of first ionization energies in transition metals?

• A. (A) First ionization energies increase from left to right for transition metals in all rows.
• B. (B) A greater increase from left to right is seen in the third row than in the first and second rows.
• C. (C) They increase from left to right for only the first row of transition metals.
• D. (A) and (B) are correct.
• E. all of the above

Answer: (E)

Verified step by step guidance

1. Understand the concept of first ionization energy: It is the energy required to remove the outermost electron from a neutral atom in its gaseous state.
2. Recognize the general trend in the periodic table: For main group elements, first ionization energy generally increases across a period from left to right due to increasing nuclear charge and decreasing atomic radius.
3. Consider transition metals: Unlike main group elements, transition metals have electrons added to the d subshell, which can affect the trend in ionization energies.
4. Analyze the trend for transition metals: In the first row of transition metals, ionization energies generally increase from left to right, but this trend is less pronounced in the second and third rows due to electron-electron repulsions and the filling of d orbitals.
5. Evaluate the options: Option (A) is incorrect because the trend is not consistent across all rows. Option (B) is correct as the third row shows a greater increase. Option (C) is correct for the first row. Therefore, the correct answer is that all of the above statements are true.