in which layer of the atmosphere do the radio wave signals bounces off? Explain the importance of this characteristic to use​

The ionosphere is ionized by solar radiation. It plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on the Earth.Hope it helps...

As explained below.

Explanation:

The theory of the Alfred Wegener is of the continental drift  and he gave the evidence such as the jigsaw fit and the geologic of the landforms and the continental masses and the similarity of the rocks and the origin of the glaciers, the forms of the biological aspects of the Alfred Wegener includes the flora and the fauna and  the species diversity such as those indicated by the fossil records The geologic diversity examples include the formation of the rocks and the structural changes over the time as indicated by the sea floor spreading and the formation of the plates tectonics. Climatic evidence as presented by the Wagner was that atmospheric and the climates at the time of the formation of the superlandmasses that got separated when the landmass began to drift