Explanation The chemical formula CH₃COOH represents acetic acid , a weak organic acid commonly found in vinegar. Key Information : Common Name : Acetic acid (systematic name: ethanoic acid). Properties : Weak acid (partially dissociates in water). Pungent smell, sour taste (vinegar contains ~4–8% acetic acid).

Explanation Xylem and Phloem are specialized conducting tissues in vascular plants: Xylem : Transports water and minerals from roots to other parts (unidirectional). Phloem : Transports sugars (photosynthates) from leaves to other parts (bidirectional).

Explanation The atomic weight of Mercury (Hg) is 200.59 unified atomic mass units (u), as listed on the periodic table. Key Information : Symbol : Hg (from Latin Hydrargyrum) Atomic Number : 80 Standard Atomic Weight : 200.592 u (often rounded to 200.59 u).

Explanation The mass of Earth is approximately 6.0 x 10^24 kilograms ( 5.98 x 10^24 kg ). This is a widely accepted scientific value , based on various measurements and calculations, including: Gravity measurements Satellite orbits Seismological data Planetary formation models

Explanation Longitudinal Wave (Primary Nature): Sound propagates as compressions and rarefactions (particles vibrate parallel to wave direction). Example: Sound waves in air. Mechanical Wave (Medium Dependency): Requires a medium (solid, liquid, gas) to travel—cannot propagate in a vacuum. Transverse Wave (In Specific Cases): In solids, sound can also exhibit transverse wave components (particles vibrate perpendicular to the wave direction).

Explanation Active voice: " Did you catch the fly? " (past simple, interrogative) Passive voice: Start with " Was " (since " fly " is singular and past tense is used) " catch " → " caught " (past participle) Subject " you " comes after " by " Correct passive voice: Was the fly caught by you? Explanation Negative imperative sentence → passive voice starts with "Let... not be + past participle" " Do not pay " → "Let... not be paid" Object " him " becomes the subject in passive. Correct passive voice: Let him not be paid anything. Explanation Imperative sentence → passive voice starts with " Let " Base verb " strike off " → past participle is " struck off " Structure : Let + object + be + past participle Correct passive voice: Let his name be struck off. Explanation Tense : Future simple (will buy) Passive structure : will be + past participle " buy " → bought (past participle) Subject " he " → him Reflexive pronoun remains: for himself Correct passive voice: A ticket will be bought by him for himself. Explanation Tense : Present simple (They buy) Passive structure : Object + is/are + past participle + by + subject " Flowers " is plural → use " are " Past participle of buy is bought Correct passive voice: Beautiful flowers are bought by them. Explanation This is an interrogative sentence (yes/no question). " Did you see " → "I had seen" (past simple → past perfect) " my " → "her" " this room " → "that room" " said to " → "asked" We can use " if " or " whether " in indirect questions. So both are correct : She asked me whether I had seen her daughter in that room. She asked me if I had seen her daughter in that room. Explanation The sentence expresses a wish or prayer , so in indirect narration we use " prayed ". Changes: " May " → "might" " here " → "there" So, the correct indirect narration is: They prayed that train might reach there in time. Explanation This is a question sentence in indirect narration. Changes : " said to " → " asked " " were you sitting " → " they had been sitting " (past continuous → past perfect continuous) " here " → " there " So, the correct narration is: He asked them why they had been sitting there. Explanation Direct speech: " I broke my pencil today ." Changes in indirect speech: " I " → "she" " broke " (past) → "had broken" (past perfect) " my " → "her" " today " → "that day" So, the correct indirect narration is: She said to him that she had broken her pencil that day. Explanation Direct speech : " You are my best friend. " Indirect speech : Pronouns and tense change: " You " → " I " " are " (present) → " was " (past) " my " → " his " So the correct narration is: He said that I was his best friend.

Explanation Pakistan  is the  most successful  national field hockey team in the  Hockey World Cup . Pakistanis the   four-time  champion:  1971 1978 1982 1994

Explanation The hertz is the unit of frequency  of one cycle per second.   symbol: hertz (Hz) Hertz in honor of the German physicist Heinrich Hertz hertz in the International System of Units (SI) frequency i s defined as one cycle per second *** Explanation Exponential notation (scientific notation) is used to express very small (e.g., 0.0000001) or very large (e.g., 1000000000) quantities compactly by representing numbers as powers of 10 . Key Information : Format : a × 10^n, where 1 ≤ a < 10 and n is an integer. Used for very large or very small numbers . Examples: Large number : 6.022 × 10^23 ( Avogadro's number ) Small number : 1.6 × 10^-19 ( Charge of an electron ) Explanation Marconi  invented  Radio . Radio was invented in  1895 . Guglielmo Marconi was an  Italian  inventor.  ***** Explanation The Mole (mol) is the SI unit of amount of substance, representing 6.022 x 10^23 particles. It is used to measure the amount of a substance in a sample. Explanation Louis Pasteur (1822–1895) was a pioneering microbiologist and chemist whose work bridged both fields: As a Chemist : Discovered molecular chirality (optical isomers). Studied fermentation, proving it was caused by microorganisms. As a Microbiologist : Developed pasteurization (heat treatment to kill microbes in food). Created vaccines for rabies and anthrax. Disproved spontaneous generation (germ theory of disease). Explanation The chemical formula CH₃COOH represents acetic acid , a weak organic acid commonly found in vinegar. Key Information : Common Name : Acetic acid (systematic name: ethanoic acid). Properties : Weak acid (partially dissociates in water). Pungent smell, sour taste (vinegar contains ~4–8% acetic acid). Explanation Xylem and Phloem are specialized conducting tissues in vascular plants: Xylem : Transports water and minerals from roots to other parts (unidirectional). Phloem : Transports sugars (photosynthates) from leaves to other parts (bidirectional). Explanation The atomic weight of Mercury (Hg) is 200.59 unified atomic mass units (u), as listed on the periodic table. Key Information : Symbol : Hg (from Latin Hydrargyrum) Atomic Number : 80 Standard Atomic Weight : 200.592 u (often rounded to 200.59 u). Explanation The mass of Earth is approximately 6.0 x 10^24 kilograms ( 5.98 x 10^24 kg ). This is a widely accepted scientific value , based on various measurements and calculations, including: Gravity measurements Satellite orbits Seismological data Planetary formation models Explanation Longitudinal Wave (Primary Nature): Sound propagates as compressions and rarefactions (particles vibrate parallel to wave direction). Example: Sound waves in air. Mechanical Wave (Medium Dependency): Requires a medium (solid, liquid, gas) to travel—cannot propagate in a vacuum. Transverse Wave (In Specific Cases): In solids, sound can also exhibit transverse wave components (particles vibrate perpendicular to the wave direction).

Explanation The hertz is the unit of frequency  of one cycle per second.   symbol: hertz (Hz) Hertz in honor of the German physicist Heinrich Hertz hertz in the International System of Units (SI) frequency i s defined as one cycle per second *** Explanation Exponential notation (scientific notation) is used to express very small (e.g., 0.0000001) or very large (e.g., 1000000000) quantities compactly by representing numbers as powers of 10 . Key Information : Format : a × 10^n, where 1 ≤ a < 10 and n is an integer. Used for very large or very small numbers . Examples: Large number : 6.022 × 10^23 ( Avogadro's number ) Small number : 1.6 × 10^-19 ( Charge of an electron ) Explanation Marconi  invented  Radio . Radio was invented in  1895 . Guglielmo Marconi was an  Italian  inventor.  ***** Explanation The Mole (mol) is the SI unit of amount of substance, representing 6.022 x 10^23 particles. It is used to measure the amount of a substance in a sample. Explanation Louis Pasteur (1822–1895) was a pioneering microbiologist and chemist whose work bridged both fields: As a Chemist : Discovered molecular chirality (optical isomers). Studied fermentation, proving it was caused by microorganisms. As a Microbiologist : Developed pasteurization (heat treatment to kill microbes in food). Created vaccines for rabies and anthrax. Disproved spontaneous generation (germ theory of disease). Explanation The chemical formula CH₃COOH represents acetic acid , a weak organic acid commonly found in vinegar. Key Information : Common Name : Acetic acid (systematic name: ethanoic acid). Properties : Weak acid (partially dissociates in water). Pungent smell, sour taste (vinegar contains ~4–8% acetic acid). Explanation Xylem and Phloem are specialized conducting tissues in vascular plants: Xylem : Transports water and minerals from roots to other parts (unidirectional). Phloem : Transports sugars (photosynthates) from leaves to other parts (bidirectional). Explanation The atomic weight of Mercury (Hg) is 200.59 unified atomic mass units (u), as listed on the periodic table. Key Information : Symbol : Hg (from Latin Hydrargyrum) Atomic Number : 80 Standard Atomic Weight : 200.592 u (often rounded to 200.59 u). Explanation The mass of Earth is approximately 6.0 x 10^24 kilograms ( 5.98 x 10^24 kg ). This is a widely accepted scientific value , based on various measurements and calculations, including: Gravity measurements Satellite orbits Seismological data Planetary formation models Explanation Longitudinal Wave (Primary Nature): Sound propagates as compressions and rarefactions (particles vibrate parallel to wave direction). Example: Sound waves in air. Mechanical Wave (Medium Dependency): Requires a medium (solid, liquid, gas) to travel—cannot propagate in a vacuum. Transverse Wave (In Specific Cases): In solids, sound can also exhibit transverse wave components (particles vibrate perpendicular to the wave direction).

Explanation Biology is classified as a natural science . Because it studies living organisms and life processes through observation and experimentation. Key Points : Natural Sciences include : Biology (study of life) Physics (matter/energy) Chemistry (substances/reactions) Explanation The Surah Al Kawthar is the  shortest surah of Holy Quran (3 Verses) . The Surah Baqarah is longest  surah of Holy Quran (286 Verses). ********* Explanation In the Quran and Bible , it is mentioned that the nation of Hazrat Musa (Moses, A.S.) fasted for 40 days as an act of repentance and devotion to Allah (God). Key References : Quran (Surah Al- Baqarah 2:51, 7:142) – Mentions Musa (A.S.) fasting for 40 days on Mount Sinai while receiving the Torah. Bible (Exodus 34:28) – Confirms Moses fasted 40 days and nights without food or water. Explanation The name " Ahmed " was suggested by  Hazrat Amina (R.A)  while the name " Muhammad " was suggested by  Hazrat Abdul Mutalib. Explanation In the Fajr (pre-dawn) prayer, there is a significant gap between the Azaan (call to prayer) and the actual Namaz (prayer). This is because: Azaan is called early to announce the start of the prayer time. Namaz is delayed slightly to allow worshippers to wake up, perform ablution (Wudu), and prepare. Explanation  Holy Prophet (PBUH) and Hazrat Abu Bakar (R.A)  took shelter  in the  Cave of Soor. They found  shelter  for three days in  Ghar e Soor  They took   refuge   from the  Quraysh Allah (SWT) miraculously had a  s pider  weave a web  at the cave’s entrance  on the third day of their stay Ghar e Soor also  known  as  Jabal al-thawr ( Cave of Thawr, Mount Thawr) Located in the  lower part  of  Makkah, Saudi Arabia ** About ABU BAKAR Abu Bakr was a  sahabi , a companion of  Muhammad He was the  first Caliph  of  Islam . He was also  Muhammad's father-in-law  through  Aisha . His  real name  was Abdullah or Abul-Kaaba and  Abu Bakr was his kunya. Hazrat Abu Bakar  collected  the Quran in the form of a book Explanation The word " namaz " is of Persian origin. The Arabic word for prayer is " Salah ".  Explanation Ashra Mubashra  are those Companions of Prophet Hazrat Muhammad (P.B.U.H), who were given  Good News in their life that they will be awarded Heaven . Following is the List with Names of Ashra Mubashra: 1. Hazrat Abu Bakar (R.A) 2. Hazrat Umer Farooq (R.A) 3. Hazrat Usman (R.A) 4. Hazrat Ali (R.A) 5. Hazrat Zubair ibn-e-Awam (R.A) 6. Hazrat Talha (R.A) 7. Hazrat Abdul Rehman bin-e-Auf (R.A) 8. Hazrat Abu Obaida bin-al-Jarah (R.A) 9.  Hazrat Saad bin-e-Abi Waqas (R.A) 10. Hazrat Saeed bin-e-Zaid (R.A) Explanation Karakar pass  is located in:  Hindu  Kush , KPK Important Passes of Pakistan : 1.  Khyber Pass   connects: Peshawar to Kabul connects: Pakistan to Afghanistan Height 1070 meters, 3510 feet  2.  Bolan Pass  Connects: JCB and Sibi with Quetta  Height: 1793 meters, 5884 feet  3.  Lowari Pass   Connects: Chitral with Dir  Height: 3118 meters, 10230 feet  4.  Broghil Pass   Location: Pakistan & Afghanistan border  Height: 3798 meters, 12460 feet  5.  Malakand Pass  Connects: Dir with Chitral  Height: 1362 meters, 4468 feet  6.  Shandur pass Connects: Gupis/Gilgit with Chitral  Height: 3700 meters, 12139 feet  7.  Khanjerab Pass  (top most in Pakistan)  Other name: Friendship Gate Connects: China with Pakistan  Height: 4693 meters, 15397 feet  8.  Dorah pass Connects: Badakhshan province of Afghanistan with Chitral  Height: 4300 meters, 14108 feet  9.  Babusar Pass  Connects: Mansehra/Abbotabad with Gilgit 10.  Kohat Pass Connects: Kohat with Peshawar  11.  Khojak Pass Connects: Qilla Abdullah with Chaman 12.  Tochi Pass Connects: Ghazni with Bannu 13.  Karakar Pass Connects: Mingora with Buner  Explanation Pakistan  is the  most successful  national field hockey team in the  Hockey World Cup . Pakistanis the   four-time  champion:  1971 1978 1982 1994