Biology, physics, geology
        
                    
             
        
        
        
Explanation:
The chemical properties of an element are determined by the configuration of its electrons in orbit around its nucleus. ... See a Periodic Table of the Elements. The number of protons in the nucleus of an atom is its Atomic Number.
 
        
             
        
        
        
WhG exactly are you asking question mark
        
             
        
        
        
Answer:


Explanation:
Wave 1, 
Wave 2, 
Wave 3, 
Wave 4, 
The general equation of travelling wave is given by :

The value of  will remain the same if we take phase difference into account.
 will remain the same if we take phase difference into account. 
For first wave,



For second wave,



For the third wave,



For the fourth wave,



It is clear from above calculations that waves 1 and 3 have same time period. Also, wave 2 and 4 have same time period. Hence, this is the required solution.
 
        
             
        
        
        
Answer:
The speed of light (c)
Explanation:
The equation that relates the magnetic field component of an electromagnetic wave the the electric field component of the wave is:

where
E is the magnitude of the electric field component
B is the magnitude of the magnetic field component
c is the speed of light in a vacuum, whose value is

Re-arranging the equation to solve for B, we find:
