Answer:
Helium
Explanation:
Helium is the least reactive element, since it is a noble gas with the smallest amount of valence rings.
 
        
             
        
        
        
A. molecules are CONSTANTLY moving.
  
        
                    
             
        
        
        
Answer:
Which of the following was not a reaction to John Brown's execution because of his failed raid on Harper's Ferry ???????
Explanation:
 
        
             
        
        
        
Answer:
Induced current, I = 18.88 A
Explanation:
It is given that,
Number of turns, N = 78
Radius of the circular coil, r = 34 cm = 0.34 m
Magnetic field changes from 2.4 T to 0.4 T in 2 s.
Resistance of the coil, R = 1.5 ohms
We need to find the magnitude of the induced current in the coil. The induced emf is given by :

Where
 is the rate of change of magnetic flux,
 is the rate of change of magnetic flux,
And 



Using Ohm's law, 
Induced current, 

I = 18.88 A
So, the magnitude of the induced current in the coil is 18.88 A. Hence, this is the required solution. 
 
        
             
        
        
        
Answer:
86.6, 45°
Explanation:
The diagram explains better. 
Using vector component method:
We find the x and y components of the vectors :
For the first:
A = -50cos(0)i + 50sin(0)j
A = -50i
For the second:
B = -50cos(60)i + 50sin(60)j
B = -25i + 43.3j
The resultant vector is :
R = A + B
R = -50i - 25i + 43.3j
R = -75i + 43.3j
The magnitude is:
R = [(-75)² + (43.3)²]^½
R = 86.6m
The angle is
tanθ = (50/50) = 1
θ = 45°