Question

What is the oxidation state of Pb in $Pb{O_2}$?

Answer 1

In order to solve this question, you must be aware about the concept of oxidation states. Oxidation number, also called oxidation state, is defined as the total number of electrons that an atom either gains or loses in order to form a chemical bond with another atom.

Complete answer:
The degree of oxidation for an atom in a chemical compound is indicated by its oxidation state, which is the hypothetical charge that an atom would have if all links to atoms of various elements were entirely ionic. Integers, which can be positive, negative, or zero, are commonly used to indicate oxidation states. In rare circumstances, an element's average oxidation state is a fraction, such as 8/3 in magnetite .

In $Pb{O_2}$, oxygen has an oxidation number of $- 2$ (because it isn't a peroxide or superoxide)
Let the oxidation number of Pb be x. The oxidation numbers of all atoms must then add up to zero for the compound to be neutral.
$x + 2( - 2) = 0$
$x = + 4$
As a result, the oxidation number of Pb is $+ 4$.

Note:
Oxidation is the loss of electrons when an atom's oxidation state increases due to a chemical reaction; reduction is the gain of electrons when an atom's oxidation state decreases due to a chemical reaction. As we move down the group, the lower oxidation state of elements becomes more stable due to the inert pair effect.
So, Pb has a +2 oxidation state more stable than +4.