When a helium balloon rises in the air, it expands. if the volume of the balloon doubles, what happens to the density of the helium inside it?

Spider crabs live in the shallow regions of the ocean floor. algae tend to grow on the surface of spider crabs. the algae provide the crabs protection from predators by camouflaging them. the spider crabs give the algae shelter. what does this description suggest? 1. the algae are parasites of the spider crabs. 2. the algae and the spider crabs have a mutualistic relationship. 3. the spider crabs are commensals, and the algae are parasites. 4. the spider crabs benefit from the algae living on them. 5. the spider crabs are parasites of the algae.

Balanced rock sits on a thin spike of rock in a canyon what forces keep the rock balanced on its tiny pedestal

1. what is the difference between a learner’s license and a driver’s license?