Answer: 134 neutrons are there in the nucleus of Radon-220
Explanation:
Atomic number : It is defined as the number of electrons or number of protons present in a neutral atom.
Thus, number of protons = atomic number = 86
Mass number is the number of the entities present in the nucleus which is the equal to the sum of the number of protons and electrons.
Mass number = Number of protons + Number of neutrons 
220 = 86 + Number of neutrons 
Number of neutrons = 134
 
        
             
        
        
        
Answer:
Stupid 
Explanation:
Because there is never a answer when we are trying to find one 
 
        
             
        
        
        
Answer:
A
Explanation:
if the man doubles his force to 40 and the box was yet to move that means acceleration also doubled so your answer would be A
 
        
             
        
        
        
Answer:
The velocity of the arrow after 3 seconds is 30.02 m/s.
Explanation:
It is given that,
An arrow is shot upward on the moon with velocity of 35 m/s, its height after t seconds is given by the equation:

We know that the rate of change of displacement is equal to the velocity of an object.

Velocity of the arrow after 3 seconds will be :

So, the velocity of the arrow after 3 seconds is 30.02 m/s. Hence, this is the required solution.