If the burning of a 0.53-gram piece of magnesium results in the formation of 1.21 grams of magnesium oxide, what mass of oxygen gas was consumed?

Consider a culture medium on which only gram-positive organisms such as staphylococcus aureus colonies can grow due to an elevated nacl level. a yellow halo surrounds the growth, indicating the bacterium fermented a sugar in the medium, decreasing the ph as a result and changing the color of a ph indicator chemical. this type of medium would be referred to as a differential and enrichment culture.