Match the atomic number 2,4,8,15, and 19 with each of the following: A gaseous element with valency 2.
Open in App
Solution
A gaseous element with valency 2 is helium. Its symbol is He and atomic number is 2. It is an inert gas. A solid non metal belonging to the third period with atomic number of 15 is phosphorus with symbol P. A metal of valency 1 is potassium with symbol K. Its atomic number is 19 and is an alkali metal. An element belonging to Group 2 (alkaline earth metals) is beryllium (Be). It has atomic number of 4. A rare gas (or inert gas) is helium. Its symbol is He and atomic number is 2. Its valency is 2.