Which of these human activities is a serious threat to marine ecosystems? a) fishing in estuaries. b) dumping wastes in landfills. c) sinking chemical wastes in the ocean. d) burning wastes rather than dumping them in landfills.

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 is the empirical formula of c6h18o3? ch3o c2h5o c2h6o c2h5o5

How are the terms group and period used on the periodic table