You clap your hands and instantly hear an echo. what does this tell you about the size of the room?

The isotonic saline solution described in part a is connected to an unknown solution via a semipermeable membrane, the unknown solution level drops. based on this information, what can be said about these two solutions?

Which atom or ion is the largest? a. k b. k+ c. ca d. ca2+ e. li

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.