What is the difference between hard x-rays and soft x-rays? I mainly need to know what soft-rays are used for. :) (Can't find the right topic for this question)

X-rays with high photon energies (above 5–10keV, below 0.2–0.1nm wavelength) are called hard X-rays, while those with lower energy (and longer wavelength) are called soft X-rays. Due to their penetrating ability, hard X-rays are widely used to image the inside of objects, e.g., in medical radiography and airport security. By contrast, soft X-rays are easily absorbed in air; the attenuation length of 600 eV (~2nm) X-rays in water is less than 1 micrometer.

hope this helps

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2

according to jean piaget, in what stage of cognitive development are children able to understand conservation task?

b. preoperational

just took it