what is the number of atoms present in 6dm^3 of propane gas（C3H6）at room temperature and 1 atmosphere.

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.

Which of these statements describes the size of an atom? a. an atom is larger than a sheet of aluminum foil. b. an atom is small but can be seen with just our eyes. c. an atom is the size of a plastic building block. d. an atom is tiny and cannot be seen without magnification.

Me with the reflection question fast due tm