Bridges are made of metal and concrete. They are outside and they heat up and cool down all the time. How might this factor into the design of a bridge? (We are learning about the molecules in solids, liquids and gases)

Which of the following ocean acidification? are the most likely side effects of a ph less than 7.0 in the ocean b. more metal salts altering the ocean chemistry c. dissolution of the shells of marine organisms d. both a & b e. all of the above.

Which atom or ion is the largest? a. k b. k+ c. ca d. ca2+ e. li

The bond energy for the van der waals bond between two helium atoms is 7.9×10−4ev. assuming that the average kinetic energy of a helium atom is (3/2)kbt, at what temperature is the average kinetic energy equal to the bond energy between two helium atoms