ESSC

Some Important formulas for class 6-8

With Vicky Taragi – I'm on a streak! I've been a top fan for 4 months in a row. 🎉

How many times 3 comes in the table of 3

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✅ 𝐄𝐥𝐞𝐜𝐭𝐫𝐨𝐧𝐢𝐜 𝐂𝐨𝐧𝐟𝐢𝐠𝐮𝐫𝐚𝐭𝐢𝐨𝐧 – 𝐄𝐱𝐩𝐥𝐚𝐢𝐧𝐞𝐝 𝐒𝐢𝐦𝐩𝐥𝐲

🔵 What is Electronic Configuration?

🟢 Arrangement of electrons in different energy levels (shells, subshells, orbitals) around the nucleus.
🟢 Helps in understanding chemical properties and reactivity of elements.

🟣 Principles Governing Electron Arrangement

✅ Aufbau Principle
🔹 Electrons occupy orbitals starting from the lowest energy level.
🔹 Order: 1s → 2s → 2p → 3s → 3p → 4s → 3d → 4p …

✅ Pauli Exclusion Principle
🔹 No two electrons can have the same set of four quantum numbers.
🔹 Each orbital holds maximum 2 electrons with opposite spins.

✅ Hund’s Rule
🔹 Electrons occupy orbitals singly before pairing.
🔹 Single-occupied orbitals have electrons with the same spin.

🔴 Shells and Subshells

🟡 Shells (n = 1, 2, 3, …) → Represent energy levels.
🟡 Subshells (s, p, d, f) → Shape and capacity:
◼ s → 2 electrons
◼ p → 6 electrons
◼ d → 10 electrons
◼ f → 14 electrons

🟢 Examples of Configurations

🔵 Hydrogen (H, Z=1) → 1s¹
🔵 Oxygen (O, Z=8) → 1s² 2s² 2p⁴
🔵 Calcium (Ca, Z=20) → 1s² 2s² 2p⁶ 3s² 3p⁶ 4s²
🔵 Iron (Fe, Z=26) → 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁶

🟠 Importance of Electronic Configuration

🔹 Explains periodic properties (atomic size, ionization energy, electronegativity).
🔹 Helps in predicting valency and chemical bonding.
🔹 Basis of the Periodic Table arrangement.

📌 Quick Exam Tip: Remember the order of filling orbitals using the diagonal rule (Aufbau diagram) or the mnemonic “1s → 2s → 2p → 3s → 3p …” for fast recall.

दो मोबाइल टावर 60 मीटर की दूरी पर समतल जमीन पर खड़े हैं। उनके बीच के एक बिंदु से, उनके शीर्षों का उन्नयन कोण क्रमशः 45° और 60° है। उनकी ऊंचाई में अंतर ज्ञात कीजिए!¡!

Basic proportionality Theoram

Question of the day
What is aqua regia???