The most abundant metal in the earth’s crust is
a) silicon
b) sodium
c) carbon
d) aluminium
The most abundant metal aluminium in the earth’s crust is ……. of the total metals.
a) 20%
b) 30%
c) 12%
d) 8.2%
Aluminium oxide’s layer is about …….. thick to protect from corrosion.
a) 6nm
b) 10nm
c) 5nm
d) 4nm
Aluminium is …….metal
a) acidic
b) basic
c) amphoteric
d) none of these
The aluminium oxide layer is only stable in a pH range of ……..
a) 6.5-7.0
b) 7.5-8.0
c) 7.0-9.0
d) 8.0-10
Fe2O3 is the chemical formula of ……..
a) ferric oxide
b) ferous oxide
c) a & b both
d) iron oxide
