Which of the following elements has the highest first ionization energy?
Correct answer: C. He
- A. Cs
- B. Li
- C. He
- D. I
Explanation
Helium (He) has the highest first ionization energy. This means that it requires the most energy to remove an electron from a helium atom compared to the other elements listed. The reason for this is that helium has a full valence shell with two electrons, which makes it highly stable. As a result, it takes a significant amount of energy to overcome the strong attraction between the nucleus and the electrons in helium.
This question appeared on the KMU Centralized Admission Test 2020 paper, which you can sit online with every answer explained.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Periodic Properties and Trends
Periodic properties arise from electron configuration and effective nuclear charge, producing trends in atomic and ionic radius, ionization energy, electron affinity, electronegativity, metallic character and reactivity. Comparisons run across periods and down groups, with attention to common exceptions. The topic also relates these trends to the behavior of s-block and p-block elements.
Practise s-Block and p-Block Elements
1,359 free s-Block and p-Block Elements MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Chemistry questions like this
Chemistry is on 14 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.