We may not see notice it but plate tectonics actually have a "recycle" process. However, scientist reported that it happens in a span of 500 million years. Over the years, the oceanic crusts are pressured to the topmost layer of the mantle causing the oceanic crusts to melt and mix with the Earth's mantle. Such crust blending results to the formation of volcanoes underwater. In time, the said volcanoes would erupt causing the formation of new oceanic and continental crusts.
It’s oxidation number is +6
Answer : The balanced chemical reaction will be,

Explanation :
Balanced chemical reaction : It is defined as the reaction in which the number of atoms of individual elements present on reactant side must be equal to the product side.
If the amount of atoms of each type on the left and right sides of a reaction differs then to balance the equation by adding coefficient in the front of the elements or molecule or compound in the chemical equation.
The coefficient tell us about that how many molecules or atoms present in the chemical equation.
The given chemical reaction is,

This reaction is an unbalanced chemical reaction because in this reaction number of hydrogen bromine atoms are not balanced.
In order to balance the chemical equation, the coefficient '2' put before the
and we get the balanced chemical equation.
The balanced chemical reaction will be,
