Draw structures for the eight constitutional isomers with molecular formula c9h12 that contain a benzene ring.

Compare and contrast physical changes with chemical changes.

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.

An unknown substance has been shown to have weak covalent bonds. which of the following is most likely a property of this substance? a. high ph b. high conductivity c. low melting point d. low flammability