(i) Boron reacts with concentrated HNO3 to form nitric oxide and boric acid
(ii) Boron reacts with fused NaOHto form H2O2 and boric acid
(iii) Boron reacts with SiO2 to form SiandB2O3
(1)(i),(ii)and(iii)(2)(i)and(iii)(3)(ii)and(iii)(4)(i)and(ii)