Why X-ray can be used to see through our bodies?

all EM waves travel have same speed in vacuum

Higher frequency indicates that the wave has higher energy,

Visible light has a longer wavelength than X-ray.

By v = f (lambda) , X-ray has a higher frequency than visible light

Therefore , X-ray has a higher penetrating power穿透能力.

X-ray can pass through our body tissue except the bones or some

腫瘤... visible light has not enough energy to pass through our body