01:52:16 Which statement best describes a mole? It is used mainly for writing chemical formulas. It is used for chemical equations that have reversible reactions. It is used for directly comparing the amounts of substances. It is used mainly for dealing with fluid substances.

Which two particles are found in the center of an atom

The star betelgeuse is about 600 light-years away. if it explodes tonight, a. we'll know because debris from the explosion will rain down on us from space.b. we'll know it immediately because it will be brighter than the full moon in the sky.c. we won't know about it until 600 years from now.d. none of the above.

In order of decreasing light-transmitting capabilities of materials, which is the correct sequence? a. transparent -> translucent -> opaque b. opaque -> transparent -> translucent c. opaque -> translucent -> transparent d. translucent -> transparent -> opaque