$B _{2} O _{3}$ is the acidic oxide. On moving down the group 13, the nature of oxide changes from acidic to basic.
$\underbrace{ B _{2} O _{3}}_{\text {Acidic }} \underbrace{ Al _{2} O _{3} \text { and } Ga _{2} O _{3}}_{\text {Amphoteric }} \underbrace{ In _{2} O _{3} \text { and } Tl _{2} O _{3}}_{\text {Basic }}$
Acidic character of boron oxide may be explained on the basis of small size of boron. Due to small size there is high positive charge density on atom.
P block elements are those in which the last electron enters any of the three p-orbitals of their respective shells. Since a p-subshell has three degenerate p-orbitals each of which can accommodate two electrons, therefore in all there are six groups of p-block elements.
P block elements are shiny and usually a good conductor of electricity and heat as they have a tendency to lose an electron. You will find some amazing properties of elements in a P-block element like gallium. It’s a metal that can melt in the palm of your hand. Silicon is also one of the most important metalloids of the p-block group as it is an important component of glass.