When an oxygen atom forms an ion, its gains two electrons. what is the electrical charge of the oxygen ion? -1 -2 +2 +1

An oxygen atom has 6 valence electrons and 8 electrons in total. Electrons have a negative charge. So when it gains 2 more electrons it becomes stable because of the octet rule. So it has a negative charge of 2. The answer is -2

adding or remove a gaseous reactant or product changes the concentrations. if the concentration of reactant or product is increased, the system will shift away from the side in which concentration was increased (i.e. if the concentration of reactants is increased, the system will shift toward the products. if more products are added, the system will shift to form more reactants). conversely, if the concentration of reactant or product is decreased, the system will shift toward the side in which concentration was decreased (i.e. if reactants are removed, the system will shift to form more reactants. if the concentration of products is decreased, the equilibrium will shift toward the products).

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a patient chooses to not take a beneficial medical treatment.

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