A. Diborane has two 3-centre-2-electron bonds
B. All B–H bonds in diborane are equivalent
C. Boranes are electron-deficient compounds
D. Terminal B–H bonds are longer than bridge B–H bonds
👉 Correct option(s):
1️⃣ A and C
2️⃣ A, B and C
3️⃣ B and D
4️⃣ A, C and D


Identify the correct set regarding trihalides of Group 13:
A. Lewis acidity of BX₃ decreases from BF₃ to BI₃
B. BF₃ is a weaker Lewis acid than BCl₃
C. AlCl₃ acts as a Lewis acid
D. Boron trihalides undergo hydrolysis except BF₃
👉 Correct option(s):
1️⃣ A and C
2️⃣ B, C and D
3️⃣ A, B and D
4️⃣ B and C only

Identify the correct statements:
A. B₂O₃ is acidic in nature
B. Al₂O₃ is amphoteric
C. Tl₂O₃ is basic in nature
D. Basic character of oxides decreases down the group
👉 Correct option(s):
1️⃣ A and B
2️⃣ A, B and C
3️⃣ B and D
4️⃣ A, C and D

✅ Answer: Option 1 (A, C and D)
Boron anomalous ✔
Al³⁺ strongly hydrated → aqueous me stable nahi ❌
Ga ka m.p. Al se kam ✔
Inert pair effect down the group increase ✔

✅ Answer: Option 2 (A, C and D)
BCl₃ = strong Lewis acid ✔
AlCl₃ vapour phase me dimer (Al₂Cl₆) ❌
Diborane = electron deficient ✔
Boric acid monobasic ✔


✅ Answer: Option 1 (A, B and C)
+3 down the group unstable ✔
+1 stable due to inert pair ✔
Tl³⁺ easily reduce hota ⇒ strong oxidiser ✔
Boron B³⁺ ion nahi banata ❌

✅ Answer: Option 1 (A and C)
Diborane me 2 banana bonds ✔
Terminal & bridge bonds same nahi ❌
Boranes electron-deficient ✔
Bridge bonds longer hote hain ❌

✅ Answer: Option 2 (B, C and D)
Lewis acidity: BF₃ < BCl₃ < BBr₃ < BI₃ ✔
AlCl₃ = Lewis acid ✔
BF₃ hydrolysis nahi karta ❌ (others karte)
A statement ulta likha ❌

✅ Answer: Option 2 (A, B and C)
B₂O₃ acidic ✔
Al₂O₃ amphoteric ✔
Tl₂O₃ basic ✔
Basic character increase hota hai down the group ❌

Q1. (Assertion–Reason type)
Assertion (A): Atomic radius generally decreases from left to right in a period.
Reason (R): Nuclear charge increases while number of shells remains same.
Options:
(1) A & R both true and R is correct explanation
(2) A & R both true but R is not correct explanation
(3) A true, R false
(4) A false, R true


Q2.
Which element has maximum electronegativity?
(1) Oxygen
(2) Nitrogen
(3) Fluorine
(4) Chlorine


Question:3 Which of the following has largest atomic size?
(1) Na
(2) Mg
(3) Al
(4) Si

Question 4
Assertion (A): Ionization enthalpy generally increases from left to right in a period.
Reason (R): Atomic size decreases and nuclear charge increases across a period.
(1) A & R both true and R is correct explanation
(2) A & R both true but R is not correct explanation
(3) A true, R false
(4) A false, R true


Question:5
Assertion (A): Electron affinity of halogens is high.
Reason (R): Halogens have one electron less than noble gas configuration.
(1) A & R both true and R is correct explanation
(2) A & R both true but R is not correct explanation
(3) A true, R false
(4) A false, R true

Question:6
Assertion (A): Metallic character increases down a group.
Reason (R): Atomic size increases and ionization enthalpy decreases down the group.
(1) A & R both true and R is correct explanation
(2) A & R both true but R is not correct explanation
(3) A true, R false
(4) A false, R true