What is one thing that describes the motion in waves

What tightening torque should be used for a hexagonal head screw (not split-bolt) on a 250 kcmil conductor?

What do the atoms of elements in the same group have in common? a. they have the same atomic numbers. b. they have the same average atomic masses. c. they have the same number of electron shells. d. they have the same number of electrons in their outermost shells.

Row old is the rock laver2. if this sedimentary rock layer is truly the oldest one of marine origin, what do you think that tells usabout the formation of earth's oceans?