In the demos this week we saw an empty soda can collapse when moved from the flame of the bunsen burner to the cool beaker of water. Why did this happen? What law or laws describe this relationship?

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.