Video narration
V.D. 14 hole Molecular mass 28 hoy keno - dutoi ki soman noy? Bhabun, ekti ojana bostuke daripallay mapchhen. Tar ojon bojar jonno porichito manodonder songe tulona korchhen. Vapor density ba V.D. asole emoni ekti tulona: nirdishto obosthay gaser nirdishto ayotoner borke, eki ayotoner hydrogen-er borer songe tulona kora. Tai V.D. gaser molecular mass nije noy; eti ekti anupat. Ebar asal mor-ta dekhun. Ei tulona kono ekok-maner songe noy. Ekhane manodondo holo Hydrogen, orthat H2. Ar H2-er molecular mass holo 2. Tai ei tulonake prokrito molecular mass-e bodlate hobe reference value diye gun kore. Niyomti khub sorol: M = 2 x V.D. Jodi V.D. = 14, tahole M = 2 x 14 = 28. Sutorang V.D. holo hydrogen-er tulonay paoa comparison value, ar M holo sei tulona theke hiseb kora molecular mass. Tai shurute proshner uttor: hydrogen-er molecular mass 2 bolei V.D.-er songe 2 gun kore molecular mass hoy 28. Etai 2-er karon.