The most durable metal plating on iron to protect against corrosion is
Nickel plating
Tin plating
Copper plating
Zinc plating
Stainless steel contains iron and
Cr + Ni
Cr + Zn
Zn + pb
Fe + Cr + Ni
The oxidation state of Cr in K2Cr2O7 is
+5
+3
+6
+7
Oxidation state of Fe in Fe3O4 is
3/2
4/5
5/4
8/3
Actinides
are all synthetic elements participate.
Include element 104
have any short lived isotopes
have variable valency
Among the lanthanides the one obtained by synthetic method is
Lu
Pm
Pr
Gd
Which one of the following is an ore of silver?
Argentite
Stibnite
Haematite
Bauxite
Which one of the following elements shows maximum number of different oxidation states in its compounds?
Eu
La
Am
The lanthanide contraction is responsible for the fact that
Zr and Yt have about the same radius
Zr and Nb have similar oxidation state
Zr and Hf have about the same radius
Zr and Zn have the same oxidation state
When (NH4)2Cr2O7 is heated, the gas evolved is
N2
NO2
O2
N2O
