Question

an atom has complete K and l shells is this a metal nonmetal or noble gas justify​

Answer 1

its a noble gas because it has a configuration required to attain the inert gas configuration!

hope this helps!

Answer 2

if K and I shells are complete then surely its electronic configuration will be-

2,8 so its atomic no. will be 10 and the element would be most probably Neon which is a noble gas and noble gases always remain with 8 in their last shell.