In which sample of water do the molecules have the highest average kinetic energy 1)20. ml at 100.°c 2)40. ml at 80. °c 3)60. ml at 60.° c 4)80. ml at 40.° c

Which process does not require the presence of a physical substance in order to transfer heat? air in the atmosphere is heated by the ground. this warm air then rises, and cooler air falls. this is an example of what type of process? how is conduction different from radiation?

Aperfume bottle is dropped in the corner of a room. the odor of the perfume can be detected on the other side of the room. which statement best describes this observation?

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.