Class 9th Chemistry Chapter 1 ke sab se zyada important short questions aur unke mukhtasir jawabat kya hain?

Class 9th Chemistry Chapter 1 (**Fundamentals of Chemistry / Chemistry ke Buniadi Tasawurat**) ke sab se zyada important short questions aur unke mukhtasir jawab yeh hain: --- ### **1. Industrial Chemistry aur Biochemistry mein kya farq hai?** * **Industrial Chemistry:** Is mein commercial paimane (large scale) par chemical compounds banane ke tareeqon ka mutalia kiya jata hai. * **Biochemistry:** Is mein zinda ajsam (living organisms) ke andar paaye jaane wale chemicals ki saakht (structure) aur chemical reactions ka mutalia kiya jata hai. --- ### **2. Empirical Formula aur Molecular Formula mein farq likhein.** * **Empirical Formula:** Yeh kisi compound mein maujood elements ke atoms ki sab se sadeatareen (simplest) ratio ko zahir karta hai (e.g., Glucose ka empirical formula $\text{CH}_2\text{O}$ hai). * **Molecular Formula:** Yeh kisi molecule mein maujood tamam elements ke asal (actual) atoms ki tadaad ko zahir karta hai (e.g., Glucose ka molecular formula $\text{C}_6\text{H}_{12}\text{O}_6$ hai). --- ### **3. Relative Atomic Mass ki tareef karein.** Kisi element ke atom ka woh ausat (average) mass jo Carbon-12 ($^{12}\text{C}$) ke $1/12\text{th}$ hissey se compare karke nikala jaye, usay **Relative Atomic Mass** kehte hain. Iska unit **amu** (atomic mass unit) hota hai. --- ### **4. Avogadro's Number se kya murad hai?** Kisi bhi substance ke 1 mole mein maujood particles ($atoms$, $molecules$, ya $ions$) ki makhsoos tadaad ko **Avogadro's Number** kehte hain. Iski value $6.022 \times 10^{23}$ hoti hai aur isey $N_A$ se zahir kiya jata hai. --- ### **5. Cation aur Anion mein kya farq hai?** * **Cation:** Jab koi atom electron khota (lose) karta hai, to us par positive charge aata hai (e.g., $\text{Na}^+$). * **Anion:** Jab koi atom electron haasil (gain) karta hai, to us par negative charge aata hai (e.g., $\text{Cl}^-$). --- Agar aap ko kisi specific topic ya numerical mein madad chahiye, to zaroor poochein!