Which elements of group $13$ possess both $+1$ and $+3$ oxidation state?

$H_3BO_3$ $\xrightarrow{T_1} X$ $\xrightarrow{T_2} Y$ $\xrightarrow{\text{red hot}} B_2O_3$
If $T_1 < T_2$,then $X$ and $Y$ respectively are:

Why is boric acid considered as a weak acid?

Identify the correct statements about $p$-block elements and their compounds.
$(A)$ Non-metals have higher electronegativity than metals.
$(B)$ Non-metals have lower ionisation enthalpy than metals.
$(C)$ Compounds formed between highly reactive non-metals and highly reactive metals are generally ionic.
$(D)$ The non-metal oxides are generally basic in nature.
$(E)$ The metal oxides are generally acidic or neutral in nature.

Aluminum dissolves in mineral acids and aqueous alkalis and thus shows amphoteric character. $A$ piece of aluminum foil is treated with dilute hydrochloric acid or dilute sodium hydroxide solution in a test tube and on bringing a burning match stick near the mouth of the test tube,a pop sound indicates the evolution of hydrogen gas. The same activity when performed with concentrated nitric acid,the reaction does not proceed. Explain the reason.

Tincal is