High energy wave with a very short wavelengh ex used to see bones inside an organism

because u need two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei to form isotopes.

so since they all have the same shape? i mean maybe because m& m and reeses are both chocolates

i think   the answer is c hope i'm right

oxygen, selenium, tellurium, and polonium.

they're all from the same group as sulfur (group 16).