Which of the following statements is not true?

Which of the following processes will not yield anhydrous $AlCl_3$?

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.

Which of the following is true for an element belonging to group $13$ of the periodic table?

The correct statements from the following are:
$(A)$ Ionic radii of trivalent cations of group $13$ elements decrease down the group.
$(B)$ Electronegativity of group $13$ elements decreases down the group.
$(C)$ Among the group $13$ elements,Boron has the highest first ionisation enthalpy.
$(D)$ The trichlorides and triiodides of group $13$ elements are covalent in nature.
Choose the correct answer from the options given below:

Borax,on being heated strongly above its melting point,melts to a liquid and then solidifies to a transparent mass commonly known as a Borax Bead. This transparent glassy mass consists of: