Answer:
Frequency, 
Explanation:
Given that,
The wavelength of the x-rays, 
We need to find the frequency of an x-ray. All electromagnetic wave travel with a speed of light. It is given by the formula as :

f is the frequency

So, the frequency of an x-ray is
. Hence, this is the required solution.
I don't think you mean 'criteria'. I think you mean three occurrences or
observations that indicate the presence of acceleration.
They are:
-- an object is speeding up
-- an object is slowing down
-- the direction of an object's motion is changing .
Any one of these changes is acceleration.
There's a single term that covers them all. It is "change in velocity".
Is that a question? If it is not what its the question?
All of the electromagnetic energy radiated from the sun (and from
other stars) is the product of nuclear fusion in its core.
Answer:
Active—A volcano is active if it is erupting, or may erupt soon. ...
Dormant—A dormant volcano is one that may have erupted before, but it is no longer erupting. ...
Extinct—An extinct volcano is not erupting and will never erupt again.
Explanation: