Which of the following are clues that a chemical reaction may have taken place?

A. Temperature remains constant

B. Release of heat

C. Formation of a solid

D. Mass increase

Which is not a device for reproducing sound? MP3 player microphone gramophone phonograph

Why hydrogen atom does not emit X-rays? a) it has only one electron b) it has narrow energy levels c) it has far apart energy levels d) it is the lightest patricle.

In all ecosystems energy is eventually lost to the environment via

What can accurately be said about a resultant wave that displays both reinforcement and interference? A. Molecules remain in their normal positions at spots of reinforcement. B.

What is primary sex organs called

If you have a beam perfectly balanced on a fulcrum and put a weight at the very end of one side, is there a way to know where you should put a heavier object on the other end?

Most of the Earth's volcanoes occuWhen fossils or minerals form, certain unstable elements are sometimes locked into them.

a man is standing on the edge of a 20.0m high cliff. he throws a rock vertically with an initial velocity of 10.0m/s. how high does the rock go?

The slope of a velocity time graph over any interval of time gives the during that interval

if light travels in a vacuum at 3.00 x 10^8m/s and its frequency is 7.44 x 10^7 what is its wavelength