Element Y Is a Gas at room temperature
Is a Nonmetal and has no electrical
conductivity
Is completely unreactive and inert
Has an average atomic mass that is 3.33
times greater than the standard for atomic
mass(Carbon-12)

Copper, silver, aluminum, cobalt, chromium, mercury 

1. o2(g)as a product

Non metal is an element or substance that is not a metal metal is a solid material that is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivitymetalloid is an element (e.g., germanium or silicon) whose properties are intermediate between those of metals and solid nonmetals. they are electrical semiconductors.

Ithink the answer is d