Write the chemical reactions of lanthanoids $(Ln)$ with the following:
$(1)$ With acid:
$2Ln + 6HCl \rightarrow 2LnCl_3 + 3H_2$
$(2)$ With halogens ($X_2$,where $X = F, Cl, Br, I$):
$2Ln + 3X_2 \rightarrow 2LnX_3$

(N/A) Lanthanoids are highly reactive metals.
$(1)$ They react with dilute acids to liberate hydrogen gas: $2Ln + 6HCl \rightarrow 2LnCl_3 + 3H_2$.
$(2)$ They react with halogens $(X_2)$ upon heating to form trihalides: $2Ln + 3X_2 \rightarrow 2LnX_3$.