Answer:
A. 
Explanation:
Earth is composed of different layers and one layer moves over another due to differences in the densities.
According to the physics of density, a substance having less density floats over a higher density substance. The oceanic crust has more density than the continental crust that is why continental crust float over oceanic crust. 
So in the given example, plate B is moving below the plate A, it means plate B is more dense than plate A because plate B is composed of oceanic crust
. <u>For example : continents float over the asthenosphere (a layer below the lithosphere).</u>
Hence, the correct answer is "A
".
 
        
             
        
        
        
The answer to this question would be: a spring scale.
The spring scale that you use to determine your body weight is actually a device that measures your body gravitational force. The force itself influenced by your body weight, that is why it can determine your body weight.
More weight means more force, more force will shrink the spring more.
        
             
        
        
        
Answer:
Yes,in fact visible 'light' is a form of radiation, which can be defined as an energy that travels in the form of electromagnetic waves. It can also be described as a flow of particle-like 'wave-packets', called photons, that travel constantly at the speed of light (about 300 000 kilometres per second).
Explanation:
 
        
             
        
        
        
Answer:
Condensation
Explanation:
The phase change in which a substance changes from a gas to liquid is Condensation.
There are  3 natural states of matter;
Solids, Liquids, and Gases.
Matter under certain conditions can change from one state to another. When Solids are heated they change into Liquids through the process of Heating. Upon cooling, the Liquids convert to Solid through freezing. When a Liquid such as water is heated, it converts into the Gaseous state through evaporation. Upon cooling, the Gas converts back into the Liquid state through Condensation.
 
        
             
        
        
        
Currently, many researchers are still working to find them.
Currently , its only theorized and they should be based on  the quantum and particle theory
hope this helps