३० मे २०१५
- ११:०७११:०७, ३० मे २०१५ फरक इति +२७७ न निष्क्रिय वायू नवीन पान: in periodic table the last group(18)called as noble gases because their outermost cells is fulfill and valency is zero. They do not take part in any chemical reaction.the... खूणपताका: रिकामी पाने टाळा