A chemical change occurs when... A the identity of a substance changes but its appearance does not.

B neither the appearance of a substance nor its identity changes.

C both the physical properties of a substance and its identity change.
D
the appearance of a substance changes but its identity does not.

Recent research by marine biologists suggests that bottlenose dolphins have names for themselves. scientists played sounds they had identified as the names of particular dolphins, putting them through a synthesizer so that they did not sound like the voices of particular dolphins. the researchers found that dolphins would respond to the names of other dolphins that they were related to or associated with, but they ignored the names of strangers. this discovery suggests a much greater degree of self-awareness in aquatic mammals than was previously suspected. if this research holds up, what does it suggest about dolphins?

Contrast how pollination is different among gymnosperms and angiosperms.

List five ways we are indebted to phytoplankton