
The electron affinities of which group of elements are positive?
(A) VIA
(B) IVA
(C) IA
(D) Zero
Answer
152.1k+ views
Hint: In chemistry, the term electronic affinity or electron gain enthalpy refers to the change in energy of a neutral atom or molecule which is in the gaseous state when an extra electron is added to it to form a negative ion.
Complete step by step answer: The electron affinity of an atom or molecule generally depends upon the following factors: (a) the effective nuclear charge, (b) the size of the atom or the molecule, (c) the stability of the valence shell electronic configuration.
If the electron affinity of an atom or a molecule is low, it will mean that the extra or additional electron is very weakly bound to the nucleus in the anion of the parent atom and so the resulting anion will be very less stable. But if the electron affinity of an atom or a molecule is high, it will mean that the extra electron is strongly bound to the nucleus in the anion of the parent atom and so the resulting anion will be more stable than the parent atom.
Generally the electron affinity tends to decrease down a group from top to bottom and tends to increase along a period from left to right as the electrons added to the energy levels become closer and closer to the nucleus. Lesser the distance, more will be the attraction and hence more will be the energy released when an electron is added. Also, the more the number of valence electrons of an atom, the more easily it will tend to accept electrons. Since noble gases have fully filled orbitals, extra energy is needed to enter the electron in the next higher shell and so noble gases have very large positive electron gain enthalpies.
Since group VI A is the chalcogens, IV A is the carbon group, I A is the alkali metal group and zero group of elements are the noble gases.
So option D is correct.
Note: If energy is released when an extra electron is added to the atom or molecule, the electron affinity for that atom or molecule is assigned a negative sign while if energy is supplied to add an extra electron to the atom or the molecule, then the electron affinity for that atom or molecule is assigned a positive sign.
Complete step by step answer: The electron affinity of an atom or molecule generally depends upon the following factors: (a) the effective nuclear charge, (b) the size of the atom or the molecule, (c) the stability of the valence shell electronic configuration.
If the electron affinity of an atom or a molecule is low, it will mean that the extra or additional electron is very weakly bound to the nucleus in the anion of the parent atom and so the resulting anion will be very less stable. But if the electron affinity of an atom or a molecule is high, it will mean that the extra electron is strongly bound to the nucleus in the anion of the parent atom and so the resulting anion will be more stable than the parent atom.
Generally the electron affinity tends to decrease down a group from top to bottom and tends to increase along a period from left to right as the electrons added to the energy levels become closer and closer to the nucleus. Lesser the distance, more will be the attraction and hence more will be the energy released when an electron is added. Also, the more the number of valence electrons of an atom, the more easily it will tend to accept electrons. Since noble gases have fully filled orbitals, extra energy is needed to enter the electron in the next higher shell and so noble gases have very large positive electron gain enthalpies.
Since group VI A is the chalcogens, IV A is the carbon group, I A is the alkali metal group and zero group of elements are the noble gases.
So option D is correct.
Note: If energy is released when an extra electron is added to the atom or molecule, the electron affinity for that atom or molecule is assigned a negative sign while if energy is supplied to add an extra electron to the atom or the molecule, then the electron affinity for that atom or molecule is assigned a positive sign.
Latest Vedantu courses for you
Grade 10 | CBSE | SCHOOL | English
Vedantu 10 CBSE Pro Course - (2025-26)
School Full course for CBSE students
₹37,300 per year
EMI starts from ₹3,108.34 per month
Recently Updated Pages
Types of Solutions - Solution in Chemistry

Difference Between Crystalline and Amorphous Solid

JEE Main Participating Colleges 2024 - A Complete List of Top Colleges

JEE Main Maths Paper Pattern 2025 – Marking, Sections & Tips

Sign up for JEE Main 2025 Live Classes - Vedantu

JEE Main 2025 Helpline Numbers - Center Contact, Phone Number, Address

Trending doubts
JEE Main 2025 Session 2: Application Form (Out), Exam Dates (Released), Eligibility, & More

JEE Main 2025: Derivation of Equation of Trajectory in Physics

Electric Field Due to Uniformly Charged Ring for JEE Main 2025 - Formula and Derivation

Degree of Dissociation and Its Formula With Solved Example for JEE

JEE Main 2025: Conversion of Galvanometer Into Ammeter And Voltmeter in Physics

Electrical Field of Charged Spherical Shell - JEE

Other Pages
JEE Advanced Marks vs Ranks 2025: Understanding Category-wise Qualifying Marks and Previous Year Cut-offs

JEE Advanced 2025: Dates, Registration, Syllabus, Eligibility Criteria and More

JEE Advanced Weightage 2025 Chapter-Wise for Physics, Maths and Chemistry

NCERT Solutions for Class 11 Chemistry In Hindi Chapter 1 Some Basic Concepts of Chemistry

Thermodynamics Class 11 Notes: CBSE Chapter 5

Learn About Angle Of Deviation In Prism: JEE Main Physics 2025
