Question

What is the oxidation number for iodine in Mg(IO3)2 ?

Answer 1

Answer: The oxidation state of iodine atom in the given compound is +5.

Explanation:

Oxidation state is the number that is assigned to an element when it gains or looses electrons. If an element gains electron, it will attain a negative oxidation state and if the element looses electrons, it will attain a positive oxidation state.

For the given chemical compound: $Mg(IO_3)_2$

We take the oxidation state of iodine atom be 'x'

Oxidation state of magnesium atom = +2

Oxidation state of oxygen atom = -2

Evaluating the oxidation state of iodine atom:

$+2+2x+6(-2)=0\\\\x=+5$

Hence, the oxidation state of iodine atom in the given compound is +5.

Answer 2

The oxidation number of iodine is 5 in Mg(IO3)2 which can be calculated as 
   Mg(IO3)2
   MgI2O6
As we know that
Mg has +2
O has -2
So,
   (+2) + 2I + 6 (-2)=0
   2 + 2I - 12 =0
   10+ 2I =0
    10 = 2I
     I =5