TestUstad
Asked in Premeth Test 11 — S and P Block, D Block and Chemical Bonding (13 March 2025) 2025Moderate

Correct order of decreasing electron affinities of group VII is:

Correct answer: B. Cl > F > Br > I

  • A. F > Cl > Br > I
  • B. Cl > F > Br > I
  • C. F < Cl < Br < I
  • D. Cl < F < Br < I

Explanation

The correct order of decreasing electron affinities for Group VII (halogens) is:Cl > F > Br > IHere's why:General Trend: Electron affinity generally decreases down a group in the periodic table. This is because the atomic radius increases, and the added electron is further from the nucleus, experiencing weaker attraction. Fluorine Anomaly: Fluorine is an exception to this trend. Although it's smaller than chlorine, it has a lower electron affinity. This is attributed to the small size of the fluorine atom and its high electron density. The added electron experiences significant repulsion from the existing electrons in the small 2p subshell, making the addition of an electron less favorable than in chlorine, which has a larger 3p subshell. Therefore, chlorine has the highest electron affinity among the halogens, followed by fluorine, then bromine, and finally iodine.

Last updated

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.

Start a free s-Block and p-Block Elements testAll s-Block and p-Block Elements MCQs

Exams that ask Chemistry questions like this

Chemistry is on 12 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.

AKU Chemistry45 MCQsDUHS Chemistry45 MCQsETEA MDCAT Chemistry45 MCQsKMU Chemistry45 MCQsMDCAT Chemistry45 MCQsNUMS Chemistry40 MCQsECAT Chemistry30 MCQsETEA Engineering Admission Test Chemistry30 MCQsGIKI Chemistry30 MCQsNED Chemistry30 MCQsNET Chemistry30 MCQsPIEAS Chemistry30 MCQs

Related questions

2. Law of octaves was proposed by

7th period of the periodic table contains normal elements:

(A), (B) and (C) are elements in the third period. The oxide of(A) is ionic, that of (B) is amphoteric and that of (C) is a giant molecule (covalent network). (A), (B) and (C) have atomic numbers in the order:

(A), (B) and (C) are elements in the third short period. Oxide of (A) is ionic, that of (B) is amphoteric and of (C) a giant molecule. (A), (B) and (C) have atomic numbers in the order of:

A gas that reacts with CaO and not with NaHCO3 is: