਀            㰀搀椀瘀 挀氀愀猀猀㴀∀猀攀氀攀挀琀攀搀ⴀ挀栀愀瀀琀攀爀猀ⴀ搀椀猀瀀氀愀礀∀㸀

Selected Subject: Chemistry

਀                㰀栀㐀㸀匀攀氀攀挀琀攀搀 䌀栀愀瀀琀攀爀㨀㰀⼀栀㐀㸀 ਀            㰀⼀搀椀瘀㸀 ਀            㰀搀椀瘀 挀氀愀猀猀㴀∀攀砀愀洀ⴀ琀礀瀀攀ⴀ猀攀氀攀挀琀椀漀渀∀㸀

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਀                㰀搀椀瘀 挀氀愀猀猀㴀∀洀愀爀欀猀ⴀ氀椀猀琀∀㸀 TEST TYPE I - 10 Questions, 10 Minutes, 10 Marks਀                    㰀氀愀戀攀氀㸀㰀椀渀瀀甀琀 琀礀瀀攀㴀∀爀愀搀椀漀∀ 渀愀洀攀㴀∀攀砀愀洀ⴀ琀礀瀀攀∀ 瘀愀氀甀攀㴀∀㈀　∀㸀 吀䔀匀吀 吀夀倀䔀 䤀䤀 ⴀ ㄀㔀 儀甀攀猀琀椀漀渀猀Ⰰ ㄀㔀 䴀椀渀甀琀攀猀Ⰰ ㄀㔀 䴀愀爀欀猀㰀⼀氀愀戀攀氀㸀 TEST TYPE III - 20 Questions, 20 Minutes, 20 Marks਀                㰀⼀搀椀瘀㸀 ਀                㰀挀攀渀琀攀爀㸀 Start Exam਀                㰀⼀挀攀渀琀攀爀㸀

਀            㰀挀攀渀琀攀爀㸀 ਀            㰀⼀挀攀渀琀攀爀㸀 ਀            㰀搀椀瘀 椀搀㴀∀焀甀椀稀∀㸀㰀⼀搀椀瘀㸀 ਀            㰀℀ⴀⴀ 儀甀攀猀琀椀漀渀 一愀瘀椀最愀琀椀漀渀 ⴀⴀ㸀 ਀ ਀ ਀        㰀搀椀瘀 椀搀㴀∀爀攀猀甀氀琀猀∀ 挀氀愀猀猀㴀∀栀椀搀搀攀渀∀㸀㰀⼀搀椀瘀㸀 ਀    㰀⼀搀椀瘀㸀 ਀    㰀猀挀爀椀瀀琀㸀 // Updated Chemistry chapters਀        挀漀渀猀琀 猀甀戀樀攀挀琀猀 㴀 笀 Chemistry: [ ਀                ∀䌀栀愀瀀琀攀爀 ㄀㨀 匀漀洀攀 䈀愀猀椀挀 䌀漀渀挀攀瀀琀猀 漀昀 䌀栀攀洀椀猀琀爀礀∀Ⰰ "Chapter 2: Structure of Atom",਀                ∀䌀栀愀瀀琀攀爀 ㌀㨀 䌀氀愀猀猀椀昀椀挀愀琀椀漀渀 漀昀 䔀氀攀洀攀渀琀猀 愀渀搀 倀攀爀椀漀搀椀挀椀琀礀 椀渀 倀爀漀瀀攀爀琀椀攀猀∀Ⰰ "Chapter 4: Chemical Bonding and Molecular Structure",਀                ∀䌀栀愀瀀琀攀爀 㔀㨀 吀栀攀爀洀漀搀礀渀愀洀椀挀猀∀Ⰰ "Chapter 6: Equilibrium",਀                ∀䌀栀愀瀀琀攀爀 㜀㨀 刀攀搀漀砀 刀攀愀挀琀椀漀渀猀∀Ⰰ "Chapter 8: Organic Chemistry- Some Basic Principles and Techniques",਀                ∀䌀栀愀瀀琀攀爀 㤀㨀 䠀礀搀爀漀挀愀爀戀漀渀猀∀Ⰰ "Chapter 10: Solutions",਀                ∀䌀栀愀瀀琀攀爀 ㄀㄀㨀 䔀氀攀挀琀爀漀挀栀攀洀椀猀琀爀礀∀Ⰰ "Chapter 12: Chemical Kinetics",਀                ∀䌀栀愀瀀琀攀爀 ㄀㌀㨀 吀栀攀 搀 愀渀搀 昀 䈀氀漀挀欀 䔀氀攀洀攀渀琀猀∀Ⰰ "Chapter 14: Coordination Compounds",਀                ∀䌀栀愀瀀琀攀爀 ㄀㔀㨀 䠀愀氀漀愀氀欀愀渀攀猀 愀渀搀 䠀愀氀漀愀爀攀渀攀猀∀Ⰰ "Chapter 16: Alcohols, Phenols and Ethers",਀                ∀䌀栀愀瀀琀攀爀 ㄀㜀㨀 䄀氀搀攀栀礀搀攀猀Ⰰ 䬀攀琀漀渀攀猀 愀渀搀 䌀愀爀戀漀砀礀氀椀挀 䄀挀椀搀猀∀Ⰰ "Chapter 18: Organic Compounds Containing Nitrogen (Amines)",਀                ∀䌀栀愀瀀琀攀爀 ㄀㤀㨀 䈀椀漀洀漀氀攀挀甀氀攀猀∀ ]਀        紀㬀 ਀        ⼀⼀ 匀愀洀瀀氀攀 焀甀攀猀琀椀漀渀猀 昀漀爀 䌀栀攀洀椀猀琀爀礀 挀栀愀瀀琀攀爀猀 const questions = {਀            ∀䌀栀愀瀀琀攀爀 ㄀㨀 匀漀洀攀 䈀愀猀椀挀 䌀漀渀挀攀瀀琀猀 漀昀 䌀栀攀洀椀猀琀爀礀∀㨀 嬀 {਀                    焀甀攀猀琀椀漀渀㨀 ∀圀栀愀琀 椀猀 琀栀攀 匀䤀 甀渀椀琀 漀昀 愀洀漀甀渀琀 漀昀 猀甀戀猀琀愀渀挀攀㼀∀Ⰰ options: ["Gram", "Mole", "Kilogram", "Pound"],਀                    愀渀猀眀攀爀㨀 ∀䴀漀氀攀∀ },਀                笀 question: "Which law states that mass is neither created nor destroyed in a chemical reaction?",਀                    漀瀀琀椀漀渀猀㨀 嬀∀䰀愀眀 漀昀 䌀漀渀猀攀爀瘀愀琀椀漀渀 漀昀 䴀愀猀猀∀Ⰰ ∀䰀愀眀 漀昀 䐀攀昀椀渀椀琀攀 倀爀漀瀀漀爀琀椀漀渀猀∀Ⰰ ∀䰀愀眀 漀昀 䴀甀氀琀椀瀀氀攀 倀爀漀瀀漀爀琀椀漀渀猀∀Ⰰ ∀䄀瘀漀最愀搀爀漀✀猀 䰀愀眀∀崀Ⰰ answer: "Law of Conservation of Mass"਀                紀Ⰰ {਀                    焀甀攀猀琀椀漀渀㨀 ∀圀栀愀琀 椀猀 琀栀攀 洀漀氀愀爀 洀愀猀猀 漀昀 眀愀琀攀爀 ⠀䠀舀传⤀㼀∀Ⰰ options: ["16 g/mol", "17 g/mol", "18 g/mol", "20 g/mol"],਀                    愀渀猀眀攀爀㨀 ∀㄀㠀 最⼀洀漀氀∀ },਀                笀 question: "Which of the following is not a pure substance?",਀                    漀瀀琀椀漀渀猀㨀 嬀∀䔀氀攀洀攀渀琀∀Ⰰ ∀䌀漀洀瀀漀甀渀搀∀Ⰰ ∀䴀椀砀琀甀爀攀∀Ⰰ ∀䄀氀氀 漀昀 琀栀攀 愀戀漀瘀攀∀崀Ⰰ answer: "Mixture"਀                紀Ⰰ {਀                    焀甀攀猀琀椀漀渀㨀 ∀圀栀愀琀 椀猀 琀栀攀 攀洀瀀椀爀椀挀愀氀 昀漀爀洀甀氀愀 漀昀 最氀甀挀漀猀攀 ⠀䌀蘀䠠脀舠传蘀⤠㼀∀Ⰰ options: ["CH₂O", "C₂H₄O₂", "C₃H₆O₃", "C₆H₁₂O₆"],਀                    愀渀猀眀攀爀㨀 ∀䌀䠀舀传∀ },਀                笀 question: "Which scientist proposed the atomic theory?",਀                    漀瀀琀椀漀渀猀㨀 嬀∀䨀漀栀渀 䐀愀氀琀漀渀∀Ⰰ ∀䨀⸀䨀⸀ 吀栀漀洀猀漀渀∀Ⰰ ∀䔀爀渀攀猀琀 刀甀琀栀攀爀昀漀爀搀∀Ⰰ ∀一椀攀氀猀 䈀漀栀爀∀崀Ⰰ answer: "John Dalton"਀                紀Ⰰ {਀                    焀甀攀猀琀椀漀渀㨀 ∀圀栀愀琀 椀猀 琀栀攀 瀀攀爀挀攀渀琀愀最攀 漀昀 漀砀礀最攀渀 椀渀 䌀伀舀㼠∀Ⰰ options: ["27.27%", "50%", "72.73%", "100%"],਀                    愀渀猀眀攀爀㨀 ∀㜀㈀⸀㜀㌀─∀ },਀                笀 question: "Which of the following has the highest number of molecules?",਀                    漀瀀琀椀漀渀猀㨀 嬀∀㄀最 漀昀 伀舀∠Ⰰ ∀㄀最 漀昀 䠀舀∠Ⰰ ∀㄀最 漀昀 䌀氀舀∠Ⰰ ∀㄀最 漀昀 䌀伀舀∠崀Ⰰ answer: "1g of H₂"਀                紀Ⰰ {਀                    焀甀攀猀琀椀漀渀㨀 ∀圀栀愀琀 椀猀 琀栀攀 瘀愀氀甀攀 漀昀 䄀瘀漀最愀搀爀漀✀猀 渀甀洀戀攀爀㼀∀Ⰰ options: ["6.022 × 10²²", "6.022 × 10²³", "6.022 × 10²⁴", "6.022 × 10²⁵"],਀                    愀渀猀眀攀爀㨀 ∀㘀⸀　㈀㈀ 휀 ㄀　눀대∀ },਀                笀 question: "Which of the following is a homogeneous mixture?",਀                    漀瀀琀椀漀渀猀㨀 嬀∀匀愀氀琀 猀漀氀甀琀椀漀渀∀Ⰰ ∀匀愀渀搀 愀渀搀 椀爀漀渀 昀椀氀椀渀最猀∀Ⰰ ∀伀椀氀 愀渀搀 眀愀琀攀爀∀Ⰰ ∀匀漀椀氀∀崀Ⰰ answer: "Salt solution"਀                紀 ],਀            ∀䌀栀愀瀀琀攀爀 ㈀㨀 匀琀爀甀挀琀甀爀攀 漀昀 䄀琀漀洀∀㨀 嬀 {਀                    焀甀攀猀琀椀漀渀㨀 ∀圀栀漀 搀椀猀挀漀瘀攀爀攀搀 琀栀攀 攀氀攀挀琀爀漀渀㼀∀Ⰰ options: ["J.J. Thomson", "Ernest Rutherford", "James Chadwick", "Niels Bohr"],਀                    愀渀猀眀攀爀㨀 ∀䨀⸀䨀⸀ 吀栀漀洀猀漀渀∀ },਀                笀 question: "Which subatomic particle has no charge?",਀                    漀瀀琀椀漀渀猀㨀 嬀∀倀爀漀琀漀渀∀Ⰰ ∀一攀甀琀爀漀渀∀Ⰰ ∀䔀氀攀挀琀爀漀渀∀Ⰰ ∀倀漀猀椀琀爀漀渀∀崀Ⰰ answer: "Neutron"਀                紀Ⰰ {਀                    焀甀攀猀琀椀漀渀㨀 ∀圀栀愀琀 椀猀 琀栀攀 洀愀砀椀洀甀洀 渀甀洀戀攀爀 漀昀 攀氀攀挀琀爀漀渀猀 椀渀 琀栀攀 䴀 猀栀攀氀氀㼀∀Ⰰ options: ["2", "8", "18", "32"],਀                    愀渀猀眀攀爀㨀 ∀㄀㠀∀ },਀                笀 question: "Which quantum number determines the shape of an orbital?",਀                    漀瀀琀椀漀渀猀㨀 嬀∀倀爀椀渀挀椀瀀愀氀 焀甀愀渀琀甀洀 渀甀洀戀攀爀∀Ⰰ ∀䄀稀椀洀甀琀栀愀氀 焀甀愀渀琀甀洀 渀甀洀戀攀爀∀Ⰰ ∀䴀愀最渀攀琀椀挀 焀甀愀渀琀甀洀 渀甀洀戀攀爀∀Ⰰ ∀匀瀀椀渀 焀甀愀渀琀甀洀 渀甀洀戀攀爀∀崀Ⰰ answer: "Azimuthal quantum number"਀                紀Ⰰ {਀                    焀甀攀猀琀椀漀渀㨀 ∀䠀漀眀 洀愀渀礀 漀爀戀椀琀愀氀猀 愀爀攀 瀀爀攀猀攀渀琀 椀渀 琀栀攀 搀ⴀ猀甀戀猀栀攀氀氀㼀∀Ⰰ options: ["1", "3", "5", "7"],਀                    愀渀猀眀攀爀㨀 ∀㔀∀ },਀                笀 question: "Which of the following is not a fundamental particle?",਀                    漀瀀琀椀漀渀猀㨀 嬀∀倀爀漀琀漀渀∀Ⰰ ∀一攀甀琀爀漀渀∀Ⰰ ∀䔀氀攀挀琀爀漀渀∀Ⰰ ∀倀栀漀琀漀渀∀崀Ⰰ answer: "Photon"਀                紀Ⰰ {਀                    焀甀攀猀琀椀漀渀㨀 ∀圀栀愀琀 椀猀 琀栀攀 攀氀攀挀琀爀漀渀椀挀 挀漀渀昀椀最甀爀愀琀椀漀渀 漀昀 挀栀爀漀洀椀甀洀 ⠀娀㴀㈀㐀⤀㼀∀Ⰰ options: ["[Ar] 3d⁴ 4s²", "[Ar] 3d⁵ 4s¹", "[Ar] 3d⁶", "[Ar] 3d⁴ 4s¹ 4p¹"],਀                    愀渀猀眀攀爀㨀 ∀嬀䄀爀崀 ㌀搀甀†㐀猀뤀∀ },਀                笀 question: "Which model of atom is known as the plum pudding model?",਀                    漀瀀琀椀漀渀猀㨀 嬀∀吀栀漀洀猀漀渀✀猀 洀漀搀攀氀∀Ⰰ ∀刀甀琀栀攀爀昀漀爀搀✀猀 洀漀搀攀氀∀Ⰰ ∀䈀漀栀爀✀猀 洀漀搀攀氀∀Ⰰ ∀儀甀愀渀琀甀洀 洀攀挀栀愀渀椀挀愀氀 洀漀搀攀氀∀崀Ⰰ answer: "Thomson's model"਀                紀Ⰰ {਀                    焀甀攀猀琀椀漀渀㨀 ∀圀栀愀琀 椀猀 琀栀攀 瘀愀氀甀攀 漀昀 琀栀攀 瀀爀椀渀挀椀瀀愀氀 焀甀愀渀琀甀洀 渀甀洀戀攀爀 昀漀爀 琀栀攀 瘀愀氀攀渀挀攀 攀氀攀挀琀爀漀渀猀 漀昀 猀漀搀椀甀洀㼀∀Ⰰ options: ["1", "2", "3", "4"],਀                    愀渀猀眀攀爀㨀 ∀㌀∀ },਀                笀 question: "Which rule states that electrons fill orbitals in order of increasing energy?",਀                    漀瀀琀椀漀渀猀㨀 嬀∀䠀甀渀搀✀猀 爀甀氀攀∀Ⰰ ∀倀愀甀氀椀 攀砀挀氀甀猀椀漀渀 瀀爀椀渀挀椀瀀氀攀∀Ⰰ ∀䄀甀昀戀愀甀 瀀爀椀渀挀椀瀀氀攀∀Ⰰ ∀䠀攀椀猀攀渀戀攀爀最 甀渀挀攀爀琀愀椀渀琀礀 瀀爀椀渀挀椀瀀氀攀∀崀Ⰰ answer: "Aufbau principle"਀                紀 ],਀            ∀䌀栀愀瀀琀攀爀 ㌀㨀 䌀氀愀猀猀椀昀椀挀愀琀椀漀渀 漀昀 䔀氀攀洀攀渀琀猀 愀渀搀 倀攀爀椀漀搀椀挀椀琀礀 椀渀 倀爀漀瀀攀爀琀椀攀猀∀㨀 嬀 {਀                    焀甀攀猀琀椀漀渀㨀 ∀䠀漀眀 洀愀渀礀 瀀攀爀椀漀搀猀 愀爀攀 琀栀攀爀攀 椀渀 琀栀攀 洀漀搀攀爀渀 瀀攀爀椀漀搀椀挀 琀愀戀氀攀㼀∀Ⰰ options: ["6", "7", "8", "9"],਀                    愀渀猀眀攀爀㨀 ∀㜀∀ },਀                笀 question: "Which group elements are known as alkali metals?",਀                    漀瀀琀椀漀渀猀㨀 嬀∀䜀爀漀甀瀀 ㄀∀Ⰰ ∀䜀爀漀甀瀀 ㈀∀Ⰰ ∀䜀爀漀甀瀀 ㄀㜀∀Ⰰ ∀䜀爀漀甀瀀 ㄀㠀∀崀Ⰰ answer: "Group 1"਀                紀Ⰰ {਀                    焀甀攀猀琀椀漀渀㨀 ∀圀栀椀挀栀 攀氀攀洀攀渀琀 栀愀猀 琀栀攀 栀椀最栀攀猀琀 攀氀攀挀琀爀漀渀攀最愀琀椀瘀椀琀礀㼀∀Ⰰ options: ["Fluorine", "Chlorine", "Oxygen", "Nitrogen"],਀                    愀渀猀眀攀爀㨀 ∀䘀氀甀漀爀椀渀攀∀ },਀                笀 question: "Which of the following has the smallest atomic radius?",਀                    漀瀀琀椀漀渀猀㨀 嬀∀䰀椀∀Ⰰ ∀一愀∀Ⰰ ∀䬀∀Ⰰ ∀刀戀∀崀Ⰰ answer: "Li"਀                紀Ⰰ {਀                    焀甀攀猀琀椀漀渀㨀 ∀圀栀漀 瀀爀漀瀀漀猀攀搀 琀栀攀 洀漀搀攀爀渀 瀀攀爀椀漀搀椀挀 氀愀眀㼀∀Ⰰ options: ["Dobereiner", "Newlands", "Mendeleev", "Moseley"],਀                    愀渀猀眀攀爀㨀 ∀䴀漀猀攀氀攀礀∀ },਀                笀 question: "Which block does calcium belong to?",਀                    漀瀀琀椀漀渀猀㨀 嬀∀猀ⴀ戀氀漀挀欀∀Ⰰ ∀瀀ⴀ戀氀漀挀欀∀Ⰰ ∀搀ⴀ戀氀漀挀欀∀Ⰰ ∀昀ⴀ戀氀漀挀欀∀崀Ⰰ answer: "s-block"਀                紀Ⰰ {਀                    焀甀攀猀琀椀漀渀㨀 ∀圀栀椀挀栀 攀氀攀洀攀渀琀 椀猀 愀 洀攀琀愀氀氀漀椀搀㼀∀Ⰰ options: ["Silicon", "Carbon", "Nitrogen", "Oxygen"],਀                    愀渀猀眀攀爀㨀 ∀匀椀氀椀挀漀渀∀ },਀                笀 question: "Which of the following has the highest ionization energy?",਀                    漀瀀琀椀漀渀猀㨀 嬀∀一愀∀Ⰰ ∀䴀最∀Ⰰ ∀䄀氀∀Ⰰ ∀匀椀∀崀Ⰰ answer: "Mg"਀                紀Ⰰ {਀                    焀甀攀猀琀椀漀渀㨀 ∀圀栀愀琀 椀猀 琀栀攀 最攀渀攀爀愀氀 攀氀攀挀琀爀漀渀椀挀 挀漀渀昀椀最甀爀愀琀椀漀渀 漀昀 渀漀戀氀攀 最愀猀攀猀㼀∀Ⰰ options: ["ns² np⁶", "ns² np⁵", "ns² np⁴", "ns² np³"],਀                    愀渀猀眀攀爀㨀 ∀渀猀눀 渀瀀瘀∠ },਀                笀 question: "Which period contains the lanthanides?",਀                    漀瀀琀椀漀渀猀㨀 嬀∀㐀琀栀∀Ⰰ ∀㔀琀栀∀Ⰰ ∀㘀琀栀∀Ⰰ ∀㜀琀栀∀崀Ⰰ answer: "6th"਀                紀 ]਀            ⼀⼀ 䄀搀搀 洀漀爀攀 挀栀愀瀀琀攀爀猀 眀椀琀栀 焀甀攀猀琀椀漀渀猀 愀猀 渀攀攀搀攀搀 };਀ // DOM elements਀        挀漀渀猀琀 猀甀戀樀攀挀琀匀攀氀攀挀琀椀漀渀 㴀 搀漀挀甀洀攀渀琀⸀最攀琀䔀氀攀洀攀渀琀䈀礀䤀搀⠀✀猀甀戀樀攀挀琀ⴀ猀攀氀攀挀琀椀漀渀✀⤀㬀 const chapterSelection = document.getElementById('chapter-selection');਀        挀漀渀猀琀 攀砀愀洀䌀漀渀昀椀最甀爀愀琀椀漀渀 㴀 搀漀挀甀洀攀渀琀⸀最攀琀䔀氀攀洀攀渀琀䈀礀䤀搀⠀✀攀砀愀洀ⴀ挀漀渀昀椀最甀爀愀琀椀漀渀✀⤀㬀 const examScreen = document.getElementById('exam-screen');਀        挀漀渀猀琀 爀攀猀甀氀琀猀匀挀爀攀攀渀 㴀 搀漀挀甀洀攀渀琀⸀最攀琀䔀氀攀洀攀渀琀䈀礀䤀搀⠀✀爀攀猀甀氀琀猀✀⤀㬀 const summaryScreen = document.getElementById('summary');਀         const chemistryCard = document.getElementById('chemistry-card');਀        挀漀渀猀琀 猀甀戀樀攀挀琀一攀砀琀䈀琀渀 㴀 搀漀挀甀洀攀渀琀⸀最攀琀䔀氀攀洀攀渀琀䈀礀䤀搀⠀✀猀甀戀樀攀挀琀ⴀ渀攀砀琀ⴀ戀琀渀✀⤀㬀 const subjectNext = document.getElementById('subject-next');਀        挀漀渀猀琀 挀栀愀瀀琀攀爀䰀椀猀琀 㴀 搀漀挀甀洀攀渀琀⸀最攀琀䔀氀攀洀攀渀琀䈀礀䤀搀⠀✀挀栀愀瀀琀攀爀ⴀ氀椀猀琀✀⤀㬀 const chapterNext = document.getElementById('chapter-next');਀        挀漀渀猀琀 搀椀猀瀀氀愀礀匀甀戀樀攀挀琀 㴀 搀漀挀甀洀攀渀琀⸀最攀琀䔀氀攀洀攀渀琀䈀礀䤀搀⠀✀搀椀猀瀀氀愀礀ⴀ猀甀戀樀攀挀琀✀⤀㬀 const selectedChaptersList = document.getElementById('selected-chapters-list');਀        挀漀渀猀琀 氀漀愀搀儀甀椀稀 㴀 搀漀挀甀洀攀渀琀⸀最攀琀䔀氀攀洀攀渀琀䈀礀䤀搀⠀✀氀漀愀搀ⴀ焀甀椀稀✀⤀㬀 const quizContainer = document.getElementById('quiz');਀        挀漀渀猀琀 焀甀攀猀琀椀漀渀一愀瘀椀最愀琀椀漀渀 㴀 搀漀挀甀洀攀渀琀⸀最攀琀䔀氀攀洀攀渀琀䈀礀䤀搀⠀✀焀甀攀猀琀椀漀渀ⴀ渀愀瘀椀最愀琀椀漀渀✀⤀㬀 const previousBtn = document.getElementById('previous');਀        挀漀渀猀琀 渀攀砀琀䈀琀渀 㴀 搀漀挀甀洀攀渀琀⸀最攀琀䔀氀攀洀攀渀琀䈀礀䤀搀⠀✀渀攀砀琀✀⤀㬀 const submitBtn = document.getElementById('submit');਀        挀漀渀猀琀 琀椀洀攀爀䐀椀猀瀀氀愀礀 㴀 搀漀挀甀洀攀渀琀⸀最攀琀䔀氀攀洀攀渀琀䈀礀䤀搀⠀✀琀椀洀攀✀⤀㬀 ਀        ⼀⼀ 嘀愀爀椀愀戀氀攀猀 let selectedSubject = '';਀        氀攀琀 猀攀氀攀挀琀攀搀䌀栀愀瀀琀攀爀猀 㴀 嬀崀㬀 let currentQuestion = 0;਀        氀攀琀 甀猀攀爀䄀渀猀眀攀爀猀 㴀 嬀崀㬀 let timer;਀        氀攀琀 琀椀洀攀䰀攀昀琀㬀 let examType = 10; // Default to 10 questions਀        氀攀琀 愀氀氀儀甀攀猀琀椀漀渀猀 㴀 嬀崀㬀 ⼀⼀ 匀琀漀爀攀 愀氀氀 焀甀攀猀琀椀漀渀猀 昀漀爀 琀栀攀 攀砀愀洀 ਀        ⼀⼀ 䔀瘀攀渀琀 䰀椀猀琀攀渀攀爀猀 chemistryCard.addEventListener('click', () => {਀            挀栀攀洀椀猀琀爀礀䌀愀爀搀⸀挀氀愀猀猀䰀椀猀琀⸀愀搀搀⠀✀猀攀氀攀挀琀攀搀✀⤀㬀 subjectNextBtn.classList.remove('hidden');਀            猀攀氀攀挀琀攀搀匀甀戀樀攀挀琀 㴀 ✀䌀栀攀洀椀猀琀爀礀✀㬀 });਀ subjectNext.addEventListener('click', () => {਀            猀甀戀樀攀挀琀匀攀氀攀挀琀椀漀渀⸀挀氀愀猀猀䰀椀猀琀⸀愀搀搀⠀✀栀椀搀搀攀渀✀⤀㬀 chapterSelection.classList.remove('hidden');਀            瀀漀瀀甀氀愀琀攀䌀栀愀瀀琀攀爀䰀椀猀琀⠀⤀㬀 });਀ chapterNext.addEventListener('click', () => {਀            椀昀 ⠀猀攀氀攀挀琀攀搀䌀栀愀瀀琀攀爀猀⸀氀攀渀最琀栀 㴀㴀㴀 　⤀ 笀 alert('Please select at least one chapter');਀                爀攀琀甀爀渀㬀 }਀            挀栀愀瀀琀攀爀匀攀氀攀挀琀椀漀渀⸀挀氀愀猀猀䰀椀猀琀⸀愀搀搀⠀✀栀椀搀搀攀渀✀⤀㬀 examConfiguration.classList.remove('hidden');਀            搀椀猀瀀氀愀礀匀攀氀攀挀琀攀搀䌀栀愀瀀琀攀爀猀⠀⤀㬀 });਀ loadQuiz.addEventListener('click', () => {਀            攀砀愀洀䌀漀渀昀椀最甀爀愀琀椀漀渀⸀挀氀愀猀猀䰀椀猀琀⸀愀搀搀⠀✀栀椀搀搀攀渀✀⤀㬀 examScreen.classList.remove('hidden');਀            攀砀愀洀吀礀瀀攀 㴀 瀀愀爀猀攀䤀渀琀⠀搀漀挀甀洀攀渀琀⸀焀甀攀爀礀匀攀氀攀挀琀漀爀⠀✀椀渀瀀甀琀嬀渀愀洀攀㴀∀攀砀愀洀ⴀ琀礀瀀攀∀崀㨀挀栀攀挀欀攀搀✀⤀⸀瘀愀氀甀攀⤀㬀 startExam();਀        紀⤀㬀 ਀        瀀爀攀瘀椀漀甀猀䈀琀渀⸀愀搀搀䔀瘀攀渀琀䰀椀猀琀攀渀攀爀⠀✀挀氀椀挀欀✀Ⰰ ⠀⤀ 㴀㸀 笀 if (currentQuestion > 0) {਀                挀甀爀爀攀渀琀儀甀攀猀琀椀漀渀ⴀⴀ㬀 showQuestion();਀            紀 });਀ nextBtn.addEventListener('click', () => {਀            椀昀 ⠀挀甀爀爀攀渀琀儀甀攀猀琀椀漀渀 㰀 攀砀愀洀吀礀瀀攀 ⴀ ㄀⤀ 笀 currentQuestion++;਀                猀栀漀眀儀甀攀猀琀椀漀渀⠀⤀㬀 }਀        紀⤀㬀 ਀        猀甀戀洀椀琀䈀琀渀⸀愀搀搀䔀瘀攀渀琀䰀椀猀琀攀渀攀爀⠀✀挀氀椀挀欀✀Ⰰ ⠀⤀ 㴀㸀 笀 clearInterval(timer);਀            猀栀漀眀刀攀猀甀氀琀猀⠀⤀㬀 });਀ // Functions਀        昀甀渀挀琀椀漀渀 瀀漀瀀甀氀愀琀攀䌀栀愀瀀琀攀爀䰀椀猀琀⠀⤀ 笀 chapterList.innerHTML = '';਀            猀甀戀樀攀挀琀猀嬀猀攀氀攀挀琀攀搀匀甀戀樀攀挀琀崀⸀昀漀爀䔀愀挀栀⠀挀栀愀瀀琀攀爀 㴀㸀 笀 const label = document.createElement('label');਀                挀漀渀猀琀 椀渀瀀甀琀 㴀 搀漀挀甀洀攀渀琀⸀挀爀攀愀琀攀䔀氀攀洀攀渀琀⠀✀椀渀瀀甀琀✀⤀㬀 input.type = 'radio';਀                椀渀瀀甀琀⸀渀愀洀攀 㴀 ✀挀栀愀瀀琀攀爀✀㬀 input.value = chapter;਀                椀渀瀀甀琀⸀愀搀搀䔀瘀攀渀琀䰀椀猀琀攀渀攀爀⠀✀挀栀愀渀最攀✀Ⰰ ⠀攀⤀ 㴀㸀 笀 if (e.target.checked) {਀                        猀攀氀攀挀琀攀搀䌀栀愀瀀琀攀爀猀 㴀 嬀挀栀愀瀀琀攀爀崀㬀 }਀                紀⤀㬀 ਀                氀愀戀攀氀⸀愀瀀瀀攀渀搀䌀栀椀氀搀⠀椀渀瀀甀琀⤀㬀 label.appendChild(document.createTextNode(chapter));਀                挀栀愀瀀琀攀爀䰀椀猀琀⸀愀瀀瀀攀渀搀䌀栀椀氀搀⠀氀愀戀攀氀⤀㬀 });਀        紀 ਀        昀甀渀挀琀椀漀渀 搀椀猀瀀氀愀礀匀攀氀攀挀琀攀搀䌀栀愀瀀琀攀爀猀⠀⤀ 笀 selectedChaptersList.innerHTML = '';਀            猀攀氀攀挀琀攀搀䌀栀愀瀀琀攀爀猀⸀昀漀爀䔀愀挀栀⠀挀栀愀瀀琀攀爀 㴀㸀 笀 const span = document.createElement('span');਀                猀瀀愀渀⸀挀氀愀猀猀一愀洀攀 㴀 ✀猀攀氀攀挀琀攀搀ⴀ挀栀愀瀀琀攀爀✀㬀 span.textContent = chapter;਀                猀攀氀攀挀琀攀搀䌀栀愀瀀琀攀爀猀䰀椀猀琀⸀愀瀀瀀攀渀搀䌀栀椀氀搀⠀猀瀀愀渀⤀㬀 });਀        紀 ਀        昀甀渀挀琀椀漀渀 猀琀愀爀琀䔀砀愀洀⠀⤀ 笀 // Get questions from selected chapters਀            愀氀氀儀甀攀猀琀椀漀渀猀 㴀 嬀崀㬀 selectedChapters.forEach(chapter => {਀                椀昀 ⠀焀甀攀猀琀椀漀渀猀嬀挀栀愀瀀琀攀爀崀⤀ 笀 allQuestions = allQuestions.concat(questions[chapter]);਀                紀 });਀             // Shuffle and select required number of questions਀            愀氀氀儀甀攀猀琀椀漀渀猀 㴀 猀栀甀昀昀氀攀䄀爀爀愀礀⠀愀氀氀儀甀攀猀琀椀漀渀猀⤀⸀猀氀椀挀攀⠀　Ⰰ 攀砀愀洀吀礀瀀攀⤀㬀 ਀            ⼀⼀ 䤀渀椀琀椀愀氀椀稀攀 甀猀攀爀 愀渀猀眀攀爀猀 userAnswers = new Array(allQuestions.length).fill(null);਀             // Start timer਀            琀椀洀攀䰀攀昀琀 㴀 攀砀愀洀吀礀瀀攀 ⨀ 㘀　㬀 ⼀⼀ ㄀ 洀椀渀甀琀攀 瀀攀爀 焀甀攀猀琀椀漀渀 startTimer();਀             // Create question navigation਀            挀爀攀愀琀攀儀甀攀猀琀椀漀渀一愀瘀椀最愀琀椀漀渀⠀⤀㬀 ਀            ⼀⼀ 䐀椀猀瀀氀愀礀 昀椀爀猀琀 焀甀攀猀琀椀漀渀 currentQuestion = 0;਀            猀栀漀眀儀甀攀猀琀椀漀渀⠀⤀㬀 }਀ function createQuestionNavigation() {਀            焀甀攀猀琀椀漀渀一愀瘀椀最愀琀椀漀渀⸀椀渀渀攀爀䠀吀䴀䰀 㴀 ✀✀㬀 for (let i = 0; i < examType; i++) {਀                挀漀渀猀琀 戀琀渀 㴀 搀漀挀甀洀攀渀琀⸀挀爀攀愀琀攀䔀氀攀洀攀渀琀⠀✀搀椀瘀✀⤀㬀 btn.className = 'question-nav-btn';਀                椀昀 ⠀椀 㴀㴀㴀 　⤀ 戀琀渀⸀挀氀愀猀猀䰀椀猀琀⸀愀搀搀⠀✀愀挀琀椀瘀攀✀⤀㬀 btn.textContent = i + 1;਀                戀琀渀⸀愀搀搀䔀瘀攀渀琀䰀椀猀琀攀渀攀爀⠀✀挀氀椀挀欀✀Ⰰ ⠀⤀ 㴀㸀 笀 currentQuestion = i;਀                    猀栀漀眀儀甀攀猀琀椀漀渀⠀⤀㬀 });਀                焀甀攀猀琀椀漀渀一愀瘀椀最愀琀椀漀渀⸀愀瀀瀀攀渀搀䌀栀椀氀搀⠀戀琀渀⤀㬀 }਀        紀 ਀        昀甀渀挀琀椀漀渀 猀栀漀眀儀甀攀猀琀椀漀渀⠀⤀ 笀 quizContainer.innerHTML = '';਀             const question = allQuestions[currentQuestion];਀            挀漀渀猀琀 焀甀攀猀琀椀漀渀䐀椀瘀 㴀 搀漀挀甀洀攀渀琀⸀挀爀攀愀琀攀䔀氀攀洀攀渀琀⠀✀搀椀瘀✀⤀㬀 questionDiv.className = 'question';਀             const questionText = document.createElement('p');਀            焀甀攀猀琀椀漀渀吀攀砀琀⸀琀攀砀琀䌀漀渀琀攀渀琀 㴀 怀␀笀挀甀爀爀攀渀琀儀甀攀猀琀椀漀渀 ⬀ ㄀紀⸀ ␀笀焀甀攀猀琀椀漀渀⸀焀甀攀猀琀椀漀渀紀怀㬀 questionDiv.appendChild(questionText);਀             question.options.forEach((option, index) => {਀                挀漀渀猀琀 漀瀀琀椀漀渀䐀椀瘀 㴀 搀漀挀甀洀攀渀琀⸀挀爀攀愀琀攀䔀氀攀洀攀渀琀⠀✀搀椀瘀✀⤀㬀 optionDiv.className = 'option';਀                 const input = document.createElement('input');਀                椀渀瀀甀琀⸀琀礀瀀攀 㴀 ✀爀愀搀椀漀✀㬀 input.name = 'answer';਀                椀渀瀀甀琀⸀瘀愀氀甀攀 㴀 漀瀀琀椀漀渀㬀 input.id = `option-${index}`;਀                椀渀瀀甀琀⸀挀栀攀挀欀攀搀 㴀 甀猀攀爀䄀渀猀眀攀爀猀嬀挀甀爀爀攀渀琀儀甀攀猀琀椀漀渀崀 㴀㴀㴀 漀瀀琀椀漀渀㬀 input.addEventListener('change', () => {਀                    甀猀攀爀䄀渀猀眀攀爀猀嬀挀甀爀爀攀渀琀儀甀攀猀琀椀漀渀崀 㴀 漀瀀琀椀漀渀㬀 updateQuestionNavigation();਀                紀⤀㬀 ਀                挀漀渀猀琀 氀愀戀攀氀 㴀 搀漀挀甀洀攀渀琀⸀挀爀攀愀琀攀䔀氀攀洀攀渀琀⠀✀氀愀戀攀氀✀⤀㬀 label.htmlFor = `option-${index}`;਀                氀愀戀攀氀⸀琀攀砀琀䌀漀渀琀攀渀琀 㴀 漀瀀琀椀漀渀㬀 ਀                漀瀀琀椀漀渀䐀椀瘀⸀愀瀀瀀攀渀搀䌀栀椀氀搀⠀椀渀瀀甀琀⤀㬀 optionDiv.appendChild(label);਀                焀甀攀猀琀椀漀渀䐀椀瘀⸀愀瀀瀀攀渀搀䌀栀椀氀搀⠀漀瀀琀椀漀渀䐀椀瘀⤀㬀 });਀             quizContainer.appendChild(questionDiv);਀             // Update navigation buttons਀            瀀爀攀瘀椀漀甀猀䈀琀渀⸀搀椀猀愀戀氀攀搀 㴀 挀甀爀爀攀渀琀儀甀攀猀琀椀漀渀 㴀㴀㴀 　㬀 nextBtn.disabled = currentQuestion === examType - 1;਀             // Update question navigation਀            甀瀀搀愀琀攀儀甀攀猀琀椀漀渀一愀瘀椀最愀琀椀漀渀⠀⤀㬀 }਀ function updateQuestionNavigation() {਀            挀漀渀猀琀 渀愀瘀䈀甀琀琀漀渀猀 㴀 焀甀攀猀琀椀漀渀一愀瘀椀最愀琀椀漀渀⸀焀甀攀爀礀匀攀氀攀挀琀漀爀䄀氀氀⠀✀⸀焀甀攀猀琀椀漀渀ⴀ渀愀瘀ⴀ戀琀渀✀⤀㬀 navButtons.forEach((btn, index) => {਀                戀琀渀⸀挀氀愀猀猀䰀椀猀琀⸀爀攀洀漀瘀攀⠀✀愀挀琀椀瘀攀✀Ⰰ ✀愀渀猀眀攀爀攀搀✀⤀㬀 if (index === currentQuestion) {਀                    戀琀渀⸀挀氀愀猀猀䰀椀猀琀⸀愀搀搀⠀✀愀挀琀椀瘀攀✀⤀㬀 }਀                椀昀 ⠀甀猀攀爀䄀渀猀眀攀爀猀嬀椀渀搀攀砀崀 ℀㴀㴀 渀甀氀氀⤀ 笀 btn.classList.add('answered');਀                紀 });਀        紀 ਀        昀甀渀挀琀椀漀渀 猀琀愀爀琀吀椀洀攀爀⠀⤀ 笀 timer = setInterval(() => {਀                琀椀洀攀䰀攀昀琀ⴀⴀ㬀 updateTimerDisplay();਀                 if (timeLeft <= 0) {਀                    挀氀攀愀爀䤀渀琀攀爀瘀愀氀⠀琀椀洀攀爀⤀㬀 showResults();਀                紀 }, 1000);਀             updateTimerDisplay();਀        紀 ਀        昀甀渀挀琀椀漀渀 甀瀀搀愀琀攀吀椀洀攀爀䐀椀猀瀀氀愀礀⠀⤀ 笀 const minutes = Math.floor(timeLeft / 60);਀            挀漀渀猀琀 猀攀挀漀渀搀猀 㴀 琀椀洀攀䰀攀昀琀 ─ 㘀　㬀 timerDisplay.textContent = `${minutes}:${seconds < 10 ? '0' : ''}${seconds}`;਀             // Add warning classes based on time left਀            琀椀洀攀爀䐀椀猀瀀氀愀礀⸀挀氀愀猀猀一愀洀攀 㴀 ✀✀㬀 if (timeLeft <= 300) { // 5 minutes਀                琀椀洀攀爀䐀椀猀瀀氀愀礀⸀挀氀愀猀猀䰀椀猀琀⸀愀搀搀⠀✀搀愀渀最攀爀✀⤀㬀 } else if (timeLeft <= 600) { // 10 minutes਀                琀椀洀攀爀䐀椀猀瀀氀愀礀⸀挀氀愀猀猀䰀椀猀琀⸀愀搀搀⠀✀眀愀爀渀椀渀最✀⤀㬀 }਀        紀 ਀        昀甀渀挀琀椀漀渀 猀栀漀眀刀攀猀甀氀琀猀⠀⤀ 笀 examScreen.classList.add('hidden');਀            爀攀猀甀氀琀猀匀挀爀攀攀渀⸀挀氀愀猀猀䰀椀猀琀⸀爀攀洀漀瘀攀⠀✀栀椀搀搀攀渀✀⤀㬀 ਀            ⼀⼀ 䌀愀氀挀甀氀愀琀攀 猀挀漀爀攀 let score = 0;਀             allQuestions.forEach((question, index) => {਀                椀昀 ⠀甀猀攀爀䄀渀猀眀攀爀猀嬀椀渀搀攀砀崀 㴀㴀㴀 焀甀攀猀琀椀漀渀⸀愀渀猀眀攀爀⤀ 笀 score++;਀                紀 });਀             const percentage = (score / examType) * 100;਀             // Display results਀            爀攀猀甀氀琀猀匀挀爀攀攀渀⸀椀渀渀攀爀䠀吀䴀䰀 㴀 怀 ਀            怀㬀 ਀            搀漀挀甀洀攀渀琀⸀最攀琀䔀氀攀洀攀渀琀䈀礀䤀搀⠀✀瘀椀攀眀ⴀ猀甀洀洀愀爀礀✀⤀⸀愀搀搀䔀瘀攀渀琀䰀椀猀琀攀渀攀爀⠀✀挀氀椀挀欀✀Ⰰ ⠀⤀ 㴀㸀 笀 showSummary();਀            紀⤀㬀 }਀ function showSummary() {਀            爀攀猀甀氀琀猀匀挀爀攀攀渀⸀挀氀愀猀猀䰀椀猀琀⸀愀搀搀⠀✀栀椀搀搀攀渀✀⤀㬀 summaryScreen.classList.remove('hidden');਀             let summaryHTML = '

Detailed Summary

';਀             allQuestions.forEach((question, index) => {਀                挀漀渀猀琀 甀猀攀爀䄀渀猀眀攀爀 㴀 甀猀攀爀䄀渀猀眀攀爀猀嬀椀渀搀攀砀崀㬀 const isCorrect = userAnswer === question.answer;਀                 summaryHTML += `਀                    㰀搀椀瘀 挀氀愀猀猀㴀∀猀甀洀洀愀爀礀ⴀ椀琀攀洀∀㸀

Question ${index + 1}: ${question.question}

਀                        㰀瀀㸀㰀猀琀爀漀渀最㸀夀漀甀爀 䄀渀猀眀攀爀㨀㰀⼀猀琀爀漀渀最㸀  ਀                                ␀笀甀猀攀爀䄀渀猀眀攀爀 簀簀 ✀一漀琀 愀渀猀眀攀爀攀搀✀紀 ਀                        㰀⼀瀀㸀

Correct Answer: ਀                            㰀猀瀀愀渀 挀氀愀猀猀㴀∀挀漀爀爀攀挀琀ⴀ愀渀猀眀攀爀∀㸀␀笀焀甀攀猀琀椀漀渀⸀愀渀猀眀攀爀紀㰀⼀猀瀀愀渀㸀

਀                    㰀⼀搀椀瘀㸀 `;਀            紀⤀㬀 ਀            猀甀洀洀愀爀礀匀挀爀攀攀渀⸀椀渀渀攀爀䠀吀䴀䰀 㴀 猀甀洀洀愀爀礀䠀吀䴀䰀㬀 }਀ // Utility function to shuffle array਀        昀甀渀挀琀椀漀渀 猀栀甀昀昀氀攀䄀爀爀愀礀⠀愀爀爀愀礀⤀ 笀 for (let i = array.length - 1; i > 0; i--) {਀                挀漀渀猀琀 樀 㴀 䴀愀琀栀⸀昀氀漀漀爀⠀䴀愀琀栀⸀爀愀渀搀漀洀⠀⤀ ⨀ ⠀椀 ⬀ ㄀⤀⤀㬀 [array[i], array[j]] = [array[j], array[i]];਀            紀 return array;਀        紀 ਀㰀⼀戀漀搀礀㸀