What number should be placed in front of NH3 to balance this chemical
equation?
___NH3 – N2 + 3H2

A. 3

B. 1

C. 4

D. 2

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.