Name an element,other than carbon,which exhibits the property of catenation up to seven or eight atoms. Are these compounds stable?

(N/A) $(i)$ Silicon is the element that exhibits the property of catenation up to seven or eight atoms.
$(ii)$ No,these compounds are not stable because they are highly reactive,especially in the presence of oxygen or moisture,due to the weak $Si-Si$ bond compared to the $C-C$ bond.