Video narration
Ab strength kaise naapen? Bond Energy (bandh urja) vah energy hai jo gaseous molecules mein kisi specified bond ke one mole ko todne ke liye chahiye. Bond todne mein energy lagti hai; bond banne par energy release hoti hai. Isliye strong bond ki bond energy zyada hoti hai. Reaction ke liye average bond energies se estimate likhte hain: Delta H = energy of bonds broken - energy of bonds formed. Ise dheere yaad rakhen: pehle todne ki energy, phir banne se mili energy ghataiye. Yah estimate hai, exact value nahin. Covalent bond mein sharing bhi hamesha barabar nahin hoti. Agar ek atom shared electrons ko zyada kheenchta hai, to Polar Bond (dhruviya bandh) banta hai. Jaise H-Cl mein chlorine electrons ko zyada kheenchta hai; chlorine side thoda negative aur hydrogen side thoda positive hota hai. Agar sharing equal ya lagbhag equal ho, jaise H2 ya Cl2 mein, to Non-polar Bond (adhruviya bandh) hota hai. Yaad rakhen, poore molecule ka polar hona uski shape par bhi depend karta hai; abhi hum bond polarity ki baat kar rahe hain. Ant mein, Van der Waals forces (vain dar vaal bal) ko chemical bond mat samajhiye. Ye alag atoms ya molecules ke beech ki bahut weak attractions hain. Inke kaaran molecules paas reh sakte hain, par ye ionic, covalent, ya metallic bonds se kamzor hote hain. To atoms kyon judte hain? Zyada stable, kam-energy arrangement paane ke liye. Lekin electron transfer, sharing, ya free movement - yahi tay karta hai ki matter kaise juda hai aur uske gun kaise honge.