An excited atom can return to its ground state by absorbing electromagnetic radiation is false about the electromagnetic radiation.
Option B
<u>Explanation</u>:
In the scope of modern quantum theory, the term Electromagnetic radiation is identified as the movement of photons through space. Almost all the sources of energy that we utilize today such as coal, oil, etc are a product of electromagnetic radiation which was absorbed from the sun millions of years ago. 
Various properties of electromagnetic radiations are a directly proportional relationship between the energy and the frequency, Inverse proportionality between frequency and the wavelength, etc. Hence, we can conclude that an "excited atom" can never return to its ground state by assimilating electromagnetic radiation and the 2nd statement is false.
 
        
             
        
        
        
The convection going on with the magma in the asthenosphere
        
                    
             
        
        
        
Answer:
C.) The amount of mass used up in holding a nucleus together.
Explanation:
The mass defect of a nucleus represents the mass of the energy binding the nucleus. It is the difference between the mass of the nucleus and the sum of the masses of the nucleons of which it is composed.
Regards!
 
        
             
        
        
        
Answer:
10 :)
You have to divide the difference of speed and divide it by the time. So 100-20 would be 80, and if you divide that by 8 it would be 10.
Hope this helps.