Chemical Bonding രാസബന്ധനം
The chapter opens at a school science exhibition, where pictures show molecules with their atoms strung together like beads on a necklace. What holds the atoms together, and why do they join at all? You will find the answer in the noble gases, whose 8 outermost electrons (the octet) make them stable. Other atoms reach that octet in two ways. A metal can give electrons to a non-metal, and the ions formed attract each other: the ionic bond of common salt and magnesium oxide. Or two non-metals share pairs of electrons: the covalent bond of H₂, O₂, N₂, water and HCl. You will learn to draw electron dot diagrams, and to use electronegativity to tell ionic from covalent and to explain polar molecules and the hydrogen bonds of water. Finally, from valency you will write the formulae of compounds, acids, bases and salts. This self-study guide starts from the basics, explains every idea step by step with animations and virtual labs, answers every textbook question, and ends with a revision sheet and a model test.
The chapter in one picture
Part 1 is the ionic bond (അയോണിക ബന്ധനം): an electron is transferred, and the opposite charges of the ions attract. Part 2 is the covalent bond (സഹസംയോജകബന്ധനം): a pair of electrons is shared. Dots belong to one fluorine atom and crosses to the other, so you can see where each shared electron comes from.
How to use this guide
🎬 Watch the animations
Electrons jump from sodium to chlorine, circles overlap to share pairs, and a shared pair slides towards the more electronegative atom, one step at a time. Press Next ▶ or ▶▶ Auto play. Animations pause by themselves when you scroll away; click a lab to start its clock again.
🧪 Use the virtual labs
Your textbook suggests the free program Ghemical for building molecules. This guide has its own labs instead: an octet checker, an electron-transfer lab, a covalent overlap builder, an electronegativity tug of war, a valency finder and a criss-cross formula machine.
✍️ Try before you see
Every textbook table is a fill-in table with a check button, and every question hides its answer behind a button. Work it out in your notebook first. The “Check yourself” quizzes at the end of each page tell you at once whether you are right.
📖 Textbook words
Purple മലയാളം words are the exact terms used in your textbook (pages 43–68), so you can match this guide with your book and write answers in either language.
🔇 Quiet and offline
The pages make no sound and need no internet. Optional "Explore online" boxes link to checked websites (no videos); they open only if you click them. Every page is a single file, so the whole guide works on a computer or phone with no connection.
Learning path
Follow the pages in order. If you already read formulae easily and can write the configuration of any element up to calcium, you can skim pages 1–2. Still try their quizzes, because the chapter uses these ideas on every page.
Scientists in this chapter
Two American chemists gave this chapter its main tools. Here they are as name cards (no photos).
Quick glossary (Malayalam ↔ English)
| Textbook term | English | Meaning |
|---|---|---|
| രാസബന്ധനം | Chemical bond | The force that holds the constituent particles together in a compound |
| ആകർഷണബലം · ഘടക കണങ്ങൾ | Force of attraction · constituent particles | The pull between particles · the atoms, ions or molecules a substance is made of |
| മൂലകം · സംയുക്തം · തന്മാത്ര | Element · compound · molecule | One kind of atom · different elements joined in a fixed ratio · a group of joined atoms |
| ഉൽകൃഷ്ട വാതകങ്ങൾ · അലസവാതകങ്ങൾ | Noble gases · inert gases | Group 18: helium, neon, argon … – stable, they generally do not react |
| അഷ്ടകവിന്യാസം | Octet configuration | 8 electrons in the outermost shell, as in the noble gases |
| രണ്ട് ഇലക്ട്രോൺ സംവിധാനം | Duplet configuration | 2 electrons in the only shell, K – helium; hydrogen reaches it by sharing |
| സ്ഥിരത | Stability | The state of an atom that has no tendency to give, take or share electrons |
| അയോണിക ബന്ധനം · ഇലക്ട്രോവാലന്റ് ബന്ധനം | Ionic bond · electrovalent bond | The electrostatic attraction between oppositely charged ions |
| അയോൺ · കാറ്റയോൺ · ആനയോൺ | Ion · cation · anion | A charged particle · a positive ion (Na⁺) · a negative ion (Cl⁻) |
| അയോണീകരണ ഊർജം · അയോണീകരണ എൻഥാൽപി | Ionisation energy · ionisation enthalpy | Energy needed to remove the most loosely held outermost electron of an isolated gaseous atom |
| ഇലക്ട്രോൺ ആർജിത എൻഥാൽപി | Electron gain enthalpy | Energy released when a neutral gaseous atom gains an electron to form a negative ion |
| ഇലക്ട്രോൺ ഡോട്ട് ഡയഗ്രം | Electron dot diagram | The symbol with its outermost electrons drawn as dots or crosses (G. N. Lewis) |
| അയോണിക സംയുക്തങ്ങൾ · ഇലക്ട്രോവാലന്റ് സംയുക്തങ്ങൾ | Ionic compounds · electrovalent compounds | Compounds formed by ionic bonds: NaCl, MgO, CaF₂ |
| പോളാർ ലായകങ്ങൾ | Polar solvents | Solvents with polar molecules, like water, that dissolve ionic compounds |
| ബാഷ്പീകരണസ്വഭാവം · കാഠിന്യം | Volatility · hardness | How easily a substance turns into vapour · resistance to scratching and breaking |
| ക്രിസ്റ്റലുകൾ | Crystals | Solids with particles in a regular repeating pattern |
| ഉരുകൽനില · തിളനില | Melting point · boiling point | The temperature at which a solid melts · a liquid boils |
| വൈദ്യുത ചാലകം | Electrical conductor | A substance that lets electricity pass |
| സഹസംയോജകബന്ധനം | Covalent bond | A chemical bond formed by sharing electrons |
| ഏകബന്ധനം · ദ്വിബന്ധനം · ത്രിബന്ധനം | Single · double · triple bond | One, two or three shared pairs: F–F, O=O, N≡N |
| ദ്വയാറ്റോമിക തന്മാത്ര | Diatomic molecule | A molecule of two atoms: H₂, O₂, N₂, F₂, Cl₂ |
| ജോഡി ഇലക്ട്രോണുകൾ · പങ്കുവയ്ക്കൽ | Electron pair(s) · sharing | Two electrons together · using electrons in common |
| സഹസംയോജക സംയുക്തങ്ങൾ | Covalent compounds | Compounds formed by covalent bonds: H₂O, HCl, CH₄, CO₂ |
| അലോഹ മൂലകങ്ങൾ | Non-metal elements | Elements such as H, C, N, O, Cl; when they combine they usually share |
| ഓർഗാനിക് ലായകങ്ങൾ | Organic solvents | Kerosene, carbon tetrachloride, benzene – they dissolve covalent compounds |
| ഇലക്ട്രോനെഗറ്റിവിറ്റി · ഇലക്ട്രോനെഗറ്റിവിറ്റി സ്കെയിൽ | Electronegativity · electronegativity scale | The relative ability of an atom in a covalent bond to attract the shared pair · Pauling's scale, 0 to 4 |
| പോളാർ സ്വഭാവം · പോളാർ തന്മാത്രകൾ | Polar nature · polar molecules | Molecules with a slightly positive end and a slightly negative end: HCl, H₂O, NH₃ |
| ഭാഗിക പോസിറ്റീവ് / നെഗറ്റീവ് ചാർജ് (δ+ / δ−) | Partial positive / negative charge | “Delta plus” and “delta minus”: small charges on the ends of a polar bond |
| സാർവിക ലായകം | Universal solvent | Water, which dissolves a very large number of substances |
| ജ്യാമിതീയ ആകൃതി | Geometrical shape | The shape of a molecule; it can cancel the pulls of polar bonds (CO₂, CCl₄) |
| ഹൈഡ്രജൻ ബന്ധനം · അന്തർതന്മാത്രാബലങ്ങൾ | Hydrogen bonding · intermolecular forces | The attraction of a δ+ hydrogen to F, O or N of a molecule · forces between molecules |
| സംയോജകത | Valency | The number of electrons an atom gives, takes or shares in a chemical reaction |
| രാസസൂത്രം · പാദാങ്കം · റാഡിക്കൽ | Chemical formula · subscript · radical | Symbols showing a compound's make-up · the small number low on the right · a group of atoms acting as one ion (SO₄²⁻) |
| ആസിഡ് · ബേസ് · ആൽക്കലി · ലവണം | Acid · base · alkali · salt | Gives H⁺ ions · gives OH⁻ ions · a base soluble in water · formed when an acid and a base react |
| ബേസികത (ഏകബേസിക, ദ്വിബേസിക) | Basicity (monobasic, dibasic) | The number of H⁺ ions one molecule of an acid gives: HCl 1, H₂SO₄ 2 |
| നിർവീരീകരണ രാസപ്രവർത്തനം · വൈദ്യുതപരമായി നിർവീര്യം | Neutralisation reaction · electrically neutral | Acid + base → salt + water · with a total charge of zero |
🌐 Explore online (optional)
Want to go further? Each teaching page ends with a few checked websites and simulations (no videos), and page 13 has the full resources hub. They need the internet; the guide itself works offline. Here you can build molecules yourself:
- 🧪 MolView MolView
Draw or search a molecule and turn it around in 3D. - 🧪 Avogadro (free molecule editor) Avogadro
Free software to build molecules – like the Ghemical program named in the textbook. - 📄 Ghemical Wikipedia
The molecule-building program the textbook asks you to use.
Made for self-learning. Works offline – every page is a single file; only the optional "Explore online" links need the internet. Study material prepared by Claude for Madhu's family study folder, October 2026.