Period 4; Group VIII
Period 5; Group VI
Period 5; Group VIII
Period 5; Group 0
Number of electrons increases down the group.
Ionization energy increases down the group.
Atomic radius increases down the group.
Nuclear charge increases down the group.
They are all gases at room temperature and pressure.
Reactivity increases down the group.
Oxidising power decreases down the group
Not all of them are diatomic, e.g. solid crystals of iodine
They are abundant and easily obtained.
They are inert.
They have low densities.
They are monoatomic.
They form coloured compounds, which can be easily separated from other reagents in reactions.
They have high melting and boiling points, which make them suitable for the high termperatures of industrial processes.
They are cheap and abundant.
They have a partially-filled d-subshell.
None of the above
It is a metal.
It has variable oxidation states.
It has high oxidising power.
It is a good catalyst.
They only exhibit +3 oxidation state.
They are hypothetical elements because they are not shown in the main block of Periodic Table.
They don't occur naturally because they are highly radioactive and decay spontaneously.
They all have valence electrons in the f-orbitals.