Why must the number of electrons lost equal the number of electrons gained in every redox reaction?

This is dictated by the law of conservation of energy even in reactions. NO energy can be destroyed or created. For an atom to gain electrons, another must have lost the electrons, and vice versa. Additionally, reactions need to be in equilibrium between both products and reactants

Adozen is 12, and your needing to calculate the weight of one medium egg, so i would do 21/12=1.75 per egg, and check your answer by doing 1.75 * 12= 21 : ) : ): ): ): ) i hoped i

The formula is (nh4)2co3