Answer:
a

b

Explanation:
From the question we are told that
The diameter is 
Generally the radius electron orbit is mathematically represented as

=> 
This radius can also be represented mathematically as

Here n is the quantum number and
is the Bohr radius with a value

So

=> 
Generally the angular momentum of the electron is mathematically represented as

Here h is the Planck constant and the value is 
m is the mass of the electron with values 
So


The stage where atoms are spread out and bouncy is the gas stage.
Answer:
Centripetal acceleration.
Explanation:
Centripetal acceleration is a property of a body moving in a uniform circular path and it is directed radially towards the center of the circle in which body is rotating.
The force which causes this acceleration is centripetal force which is also directed towards the center of the circle and pulls the body towards its center.
It is calculated through following formula

where v is velocity and r is the radius of the circle.
Answer: silicon,or maybe none.
Explanation: I searched it up not really sure sorry