A or D I think but go with A it makes more since
Answer: X: High and Y: High
Explanation: When comparing plasma with solids it is seen that solids are more denser than plasma and has less kinetic energy as compared to plasma.
So among the difference plasma will have high kinetic energy and solids will have high density in comparison with each other.
Answer:
The separation between layers of atoms in the crystal is 164.52 pm.
Explanation:
Formula used
(Bragg's law)
Where :
n = an order of reflection (integer)
= wavelength of the beam incident X-ray
d = spacing between the layer
θ = incident angle ( angle between ray and scatter plane)
We have :
λ = 157 pm
θ = 28.5°
n = 1
d = ?
(Bragg's law)

The separation between layers of atoms in the crystal is 164.52 pm.
It depends on the unit though if its in miles per hour then you can simply divide 50 by 2