When a single salt crystal is added to a cool liquid, large crystals form. Which statement about the original cool liquid is correct? A) The liquid is a heterogeneous mixture because the crystals can be easily separated from the liquid

B) The liquid is a pure substance because it was made up of a single compound

C) The liquid is a pure substance because it was uniform before the crystal was added

D) The liquid is a homogenous mixture because the substance that formed the large crystals was uniformly dissolved

Smog is the term used to describe the combination of fog and smoke

Two nitro no2 groups are chemically bonded to a patch of surface. they can't move to another location on the surface, but they can rotate (see sketch at right). it turns out that the amount of rotational kinetic energy each no2 group can have is required to be a multiple of ε, where =ε×1.010−24 j. in other words, each no2 group could have ε of rotational kinetic energy, or 2ε, or 3ε, and so forth — but it cannot have just any old amount of rotational kinetic energy. suppose the total rotational kinetic energy in this system is initially known to be 32ε. then, some heat is removed from the system, and the total rotational kinetic energy falls to 18ε. calculate the change in entropy. round your answer to 3 significant digits, and be sure it has the correct unit symbol.

What forms when chemical reactions combine pollution with sunlight?