Answer:

Explanation:
h = Planck's constant = 
m = Mass of electron = 
k = Coulomb constant = 
e = Charge of electron = 
n = 1 (ground state)
Angular momentum is given by

From Bohr's atomic model we have


The centripetal force will balance the electrostatic force

The diameter is 
Answer:
The energy lost by the atoms is given off as an electromagnetic wave. ... even if it's not very intense, will always cause electrons to be emitted.
Explanation:
Work in general is given by W=F·d where F is the force vector and d is the displacement vector. The dot symbol is the dot product which is a measure of how parallel two vectors are. It can be replaced by the cosine of the angle between the two vectors and the vectors replaced by their magnitudes. If F and d are parallel then the angle is zero and the cosine is unity. So in this case work can be defined as the product of the magnitudes of the force and distance:
W=Fd
Answer:
Catapult on the ground: Normal, gravity
Catapult (I'm assuming launching marshmallow): Reaction of Force Applied
Marshmallow: Force Applied
Explanation:
This is the forces that act on a stationary object and a launched object. The catapult may also experience a force friction if your teacher is taking a more practical sense.
I believe that is true.
hope this helps!