Why is a ripple in a pond an example of mechanical waves?

Which substances have the lowest melting points: ionic covalent, or metallic

The characteristic of two different types of reactions are shown below. reaction a: electrons are gained by the atoms of an element. reaction b: protons are lost by the atom of and element. which statement is true about the atoms of the elements that participate in the two reactions? a: their identity changes in both reaction a and b. b: their identity changes in reaction a but not b. c: their identity changes in reaction b but not a. d: their identity remains the same.

What are four significant sources of ghgs that come from wostem washington?