Class 11 Exam > Class 11 Questions > Generally, the first ionization energy increa...
Start Learning for Free
Generally, the first ionization energy increases along a period. But there are some exceptions. One which is NOT an exception is ______.
- a)Na and Mg
- b)Mg and Al
- c)N and O
- d)Be and B
Correct answer is option 'A'. Can you explain this answer?
Verified Answer
Generally, the first ionization energy increases along a period. But t...
Na and Mg are not an exception.
Most Upvoted Answer
Generally, the first ionization energy increases along a period. But t...
Explanation:
First ionization energy is the energy required to remove one electron from the outermost shell of an atom in the gaseous phase. In general, the first ionization energy increases along a period due to the following factors:
1. Increasing nuclear charge: As we move across a period, the number of protons in the nucleus increases, leading to a stronger attractive force between the nucleus and the electrons. This increased attraction makes it more difficult to remove an electron, thus increasing the ionization energy.
2. Decreasing atomic radius: As we move across a period, the atomic radius decreases due to the increasing nuclear charge and the addition of electrons to the same energy level. The closer the outermost electron is to the nucleus, the stronger the attraction, and the higher the ionization energy.
However, there are a few exceptions to this trend. For example, in the case of Na and Mg, the first ionization energy of Na (496 kJ/mol) is lower than that of Mg (738 kJ/mol), despite Na being located to the left of Mg in the periodic table.
Reasoning:
The reason for this exception lies in the electronic configurations of Na and Mg. Na has a configuration of 1s²2s²2p⁶3s¹, while Mg has a configuration of 1s²2s²2p⁶3s². In the case of Na, the electron being removed is from the 3s orbital, which is further away from the nucleus compared to the 3s² orbital of Mg. The 3s electron in Na experiences less shielding from the inner electrons, leading to a weaker attraction to the nucleus and a lower ionization energy.
Conclusion:
Therefore, when comparing Na and Mg, Na has a lower first ionization energy due to the electron being removed from a higher energy level and experiencing less nuclear attraction. Hence, option 'A' is the correct answer.
First ionization energy is the energy required to remove one electron from the outermost shell of an atom in the gaseous phase. In general, the first ionization energy increases along a period due to the following factors:
1. Increasing nuclear charge: As we move across a period, the number of protons in the nucleus increases, leading to a stronger attractive force between the nucleus and the electrons. This increased attraction makes it more difficult to remove an electron, thus increasing the ionization energy.
2. Decreasing atomic radius: As we move across a period, the atomic radius decreases due to the increasing nuclear charge and the addition of electrons to the same energy level. The closer the outermost electron is to the nucleus, the stronger the attraction, and the higher the ionization energy.
However, there are a few exceptions to this trend. For example, in the case of Na and Mg, the first ionization energy of Na (496 kJ/mol) is lower than that of Mg (738 kJ/mol), despite Na being located to the left of Mg in the periodic table.
Reasoning:
The reason for this exception lies in the electronic configurations of Na and Mg. Na has a configuration of 1s²2s²2p⁶3s¹, while Mg has a configuration of 1s²2s²2p⁶3s². In the case of Na, the electron being removed is from the 3s orbital, which is further away from the nucleus compared to the 3s² orbital of Mg. The 3s electron in Na experiences less shielding from the inner electrons, leading to a weaker attraction to the nucleus and a lower ionization energy.
Conclusion:
Therefore, when comparing Na and Mg, Na has a lower first ionization energy due to the electron being removed from a higher energy level and experiencing less nuclear attraction. Hence, option 'A' is the correct answer.
Free Test
FREE
| Start Free Test |
Community Answer
Generally, the first ionization energy increases along a period. But t...
In other 3 options I.e. b, c & d. the first element have a full filled or half filled shell and this gives them extra stability than the other element in the same option, thus they have a higher ionisation energy but in option a, the size decreases and outer shell is also fulfilled so its ionisation energy increases. so it's ionisation energy increases
|
Explore Courses for Class 11 exam
|
|
Similar Class 11 Doubts
Top Courses for Class 11View all
Generally, the first ionization energy increases along a period. But there are some exceptions. One which is NOT an exception is ______.a)Na and Mgb)Mg and Alc)N and Od)Be and BCorrect answer is option 'A'. Can you explain this answer?
Question Description
Generally, the first ionization energy increases along a period. But there are some exceptions. One which is NOT an exception is ______.a)Na and Mgb)Mg and Alc)N and Od)Be and BCorrect answer is option 'A'. Can you explain this answer? for Class 11 2025 is part of Class 11 preparation. The Question and answers have been prepared according to the Class 11 exam syllabus. Information about Generally, the first ionization energy increases along a period. But there are some exceptions. One which is NOT an exception is ______.a)Na and Mgb)Mg and Alc)N and Od)Be and BCorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for Class 11 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Generally, the first ionization energy increases along a period. But there are some exceptions. One which is NOT an exception is ______.a)Na and Mgb)Mg and Alc)N and Od)Be and BCorrect answer is option 'A'. Can you explain this answer?.
Generally, the first ionization energy increases along a period. But there are some exceptions. One which is NOT an exception is ______.a)Na and Mgb)Mg and Alc)N and Od)Be and BCorrect answer is option 'A'. Can you explain this answer? for Class 11 2025 is part of Class 11 preparation. The Question and answers have been prepared according to the Class 11 exam syllabus. Information about Generally, the first ionization energy increases along a period. But there are some exceptions. One which is NOT an exception is ______.a)Na and Mgb)Mg and Alc)N and Od)Be and BCorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for Class 11 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Generally, the first ionization energy increases along a period. But there are some exceptions. One which is NOT an exception is ______.a)Na and Mgb)Mg and Alc)N and Od)Be and BCorrect answer is option 'A'. Can you explain this answer?.
Solutions for Generally, the first ionization energy increases along a period. But there are some exceptions. One which is NOT an exception is ______.a)Na and Mgb)Mg and Alc)N and Od)Be and BCorrect answer is option 'A'. Can you explain this answer? in English & in Hindi are available as part of our courses for Class 11.
Download more important topics, notes, lectures and mock test series for Class 11 Exam by signing up for free.
Here you can find the meaning of Generally, the first ionization energy increases along a period. But there are some exceptions. One which is NOT an exception is ______.a)Na and Mgb)Mg and Alc)N and Od)Be and BCorrect answer is option 'A'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
Generally, the first ionization energy increases along a period. But there are some exceptions. One which is NOT an exception is ______.a)Na and Mgb)Mg and Alc)N and Od)Be and BCorrect answer is option 'A'. Can you explain this answer?, a detailed solution for Generally, the first ionization energy increases along a period. But there are some exceptions. One which is NOT an exception is ______.a)Na and Mgb)Mg and Alc)N and Od)Be and BCorrect answer is option 'A'. Can you explain this answer? has been provided alongside types of Generally, the first ionization energy increases along a period. But there are some exceptions. One which is NOT an exception is ______.a)Na and Mgb)Mg and Alc)N and Od)Be and BCorrect answer is option 'A'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice Generally, the first ionization energy increases along a period. But there are some exceptions. One which is NOT an exception is ______.a)Na and Mgb)Mg and Alc)N and Od)Be and BCorrect answer is option 'A'. Can you explain this answer? tests, examples and also practice Class 11 tests.
|
|
Explore Courses for Class 11 exam
|
|
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup