Respuesta :
2 oxygen atoms because the subscript is the number of atoms of that element (though if there is a coefficient then you multiply the subscript by the coefficient to get the total number of atoms of the element).
Those are the reactants, since their is not a arrow pointing to the products.
And there is a subscript '2', which means that O = 2
Answer: 2
And there is a subscript '2', which means that O = 2
Answer: 2