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See all →- Niobium forms bcc structure the density of niobium is 8.55 g/cm3 and length of unit cell edge Answer: In 0.5 g of niobium there are 1.62×10²¹ unit cells and 3.24×10²¹ atoms. Given: bcc so n = 2 atoms per unit cell, ρ = 8.55\ g cm⁻³, a... 2
- A and B each have certain number of oranges. A says to B, “ if you give me 10 of your oranges, Suppose A has x no. of oranges and B has y no. of oranges. According to the given conditions, we have x+10=2(y−10)⇒x−2y+30=0 (i) and, y+10=x... 1
- std 10th maharashtra board science part 1 gravitation notes Answer: Gravitation (Std 10 Science Part 1, Chapter 1) - solved exercise notes. 1. Match the entries and rewrite them in correct rows Quanti... 2
- M.In two moles of acetaldehyde (CH3 CHO) calculate the following a. Number of moles of carbon b. Number of moles of hydrogen Answer: (a) 4 mol C, (b) 8 mol H, (c) 2 mol O, (d) 1.2044 × 10²⁴ molecules Molecular formula of acetaldehyde: CH₃CHO = C₂H₄O. One molecule (... 1
- The density of iridium is 22.4 g/cm3 . The unit cell of iridium is fcc. Calculate the radius of iridium atom. Molar mass of iridium is 192.2 g/mol. Answer: Radius of iridium atom r ≈ 136\ pm (edge length a ≈ 385\ pm) Given: ρ = 22.4\ g cm⁻³, M = 192.2\ g mol⁻¹, fcc unit cell so n = 4 ato... 1
- E. A student used a carbon pencil to write his homework. The mass of this was found to be 5 mg. With the help of this calculate. Given: mass of carbon = 5mg = 5× 10⁻³ g Atomic mass of carbon=12u Solution :: a. The number of moles of carbon in his homework writing numbe... 1
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See all →- Why there is no 2023 and 22 pyqs Good question! Right now Doubtly has the official HSC Chemistry board papers from 2024 onwards, each with full solutions. That's 6 papers: M... 1
- Experience ending ‘…I had forgotten my wallet at home’ – SSC English March 2024 Q.7 (B) B2 narrate an experience A Lesson in Humility (sample answer) Last summer my uncle took our family to a five-star hotel to celebrate his promotion. Before we left, I... 1
- Story: Anita in a cake shop sees a small beggar boy outside – SSC English March 2024 Q.7 (B) B1 develop a story The Cake that Tasted Sweeter Anita was in a cake shop to buy a cake for her birthday. She saw a small beggar boy outside the shop, his nose... 1
- News report: ‘Child labourers rescued from stone quarries’ – SSC English March 2024 Q.7 (A) A2 Child labourers rescued from stone quarries Pune, 12th March : In a joint operation carried out on Monday morning, the district administrati... 1
- Expand the theme ‘Trees: Nature’s Gift to Man’ in 100 words – SSC English March 2024 Q.7 (A) A1 Trees are the greatest gift that nature has given to man. They give us the oxygen we breathe and take in the carbon dioxide we breathe out.... 1
- Counter-view: ‘Social networking sites are not a necessity’ – SSC English March 2024 Q.6 (B) B2 Counter-view on ‘Social networking sites are not a necessity’ I disagree with the view that social networking sites are not a necessity. It... 1
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See all →- Tourism, Transport and Communication Class 10 Notes, Questions | SSC Geography SSC Class 10 Geography Ch 9 notes: tourism, transport and communication in India and Brazil, IST vs BRT, key terms and exam Q&As.
- Economy and Occupations Class 10 Notes, Questions | SSC Geography SSC Class 10 Geography Chapter 8 notes: India vs Brazil economy, sectors, 2016 GDP data, agriculture, mining, fishing, key terms and exam qu...
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- How to Use NEET Previous Year Questions: A 4-Month Plan A month-by-month plan to use NEET previous year questions: unit-wise practice, timed sectionals, full mocks, a mistake notebook and a syllab...
- NEET Previous Year Papers 2016–2025: What 10 Years of Questions Show We tagged 2,060 questions from official NEET papers 2016–2025. See which Physics, Chemistry and Biology units grew or shrank, and what staye...
- Topics Removed from the NEET Syllabus (and How Many Questions They Had) All topics removed from the NEET syllabus, with how many questions each had in official 2016–2025 papers, and how to practise old papers.