Janelle hikes along the beach every morning at the same time. Throughout the month, she notices the shoreline follows a pattern of receding and advancing. What causes the shoreline to follow this pattern? tides

water cycle

chemical weathering

erosion and deposition

What must happen before a body cell can begin mitotic cell division

Which compound contains both ionic and covalent bonds? a) hbr b)cbr4 c)nabr d) naoh

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.