Answer:
The force constant is 
The energy stored in the spring is 
Explanation:
From the question we are told that
The mass of the object is 
The period is 
The period of the spring oscillation is mathematically represented as

where k is the force constant
So making k the subject

substituting values


The energy stored in the spring is mathematically represented as

Where x is the spring displacement which is given as

substituting values


I believe it is the first one
Option B & Option D is your correct answers.
'cause here, atom has eight electrons in it's valence shell, so it means it has stable structure which falls in group 18
Hope this helps!
True.
<span>Scientist use conversion factors to express the given value of a unit different type of unit</span>
Answer:
it takes 365 days to revolve around the star(sun)