X-rays take pictures of
your insides (bones and organs).
luggage contents.
art and statues.
all of the above.

The answer - all of the above.

X -rays are applied in many ways and for various purposes in every day life. They are defined as powerful waves of electromagnetic energy. They are able to penetrate most materials both organic and inorganic.

Their ability to penetrate organic material has made them especially useful in medicine where they can penetrate the body and reveal internal structures such as bones and organs.

In the airports, they are used for security purposes to check in luggage  bags for prohibited or dangerous items.

In  art, they are widely used by authenticators check for types of paper, materials, changes of composition and other clues to help establish authenticity of art pieces.  

when it gains or loses electrons

a 2,000 calorie based diet.