Which of the following is a covalent compound?
AlF3
Al2O3
AlCl3
Al2(SO4)3
Which of the following represents the correct outer electronic configuration of the Group 13 elements?
ns2 np1
ns2 np3
ns2 nd1
ns2 np6
Which of the following statement is correct about Group 13 elements?
they form only compounds
they form only covalent compounds
they form only co-ordinate compounds
they form both ionic and covalent compounds
Boron and aluminium are
s-block elements
p-block elements
d-block elements
f-block elements
Boron behaves as a
metal
metalloid
non-metal
transition metal
Which of the following hydroxide is most acidic in nature?
B(OH)3
Al(OH)3
In(OH)3
Ti(OH)
Which one of the following element has the highest melting point?
B
Al
Ga
Ti
Which member of Group 13 elements does not exhibit the Group valency in its compound?
boron
gallium
thallium
aluminium
In diborane, the two H — B — H angles are nearly
60º, 120º
95º, 120º
95º, 150º
120ºº, 180ºº
