fluorine (f), chlorine (cl), bromine (br), and iodine (i) are elements in the same group on the periodic table. why are these elements grouped together?

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.

If you are in grade when should you start studying for exams

Determine if the situation below is a safe practice: julia needs to hang some industrial shelving, so she carefully selects the correct drill bits for the electrical drill before attempting to screw the shelves into the wall.