What kind of electrical charge is found on the oxygen atom of a polar water molecule

The pattern of this wave changes between its beginning and end. what is true about the amplitude and wavelength of the wave when the pattern changes?

Ais a landform that is formed at the mouth of a river from the deposition of sediment carried by the river as the water flows.

18. over time, how do sand dunes tend to migrate? a. perpendicular to the movement of the wind b. in the same direction as the wind blows c. toward the wind d. in random directions