UV light is blocked from reaching the dermis by ___ in the skin. a keratin
b melanin
C vitamin D
d sebaceous glands

Atomic nuclei of almost all elements consist of

12. a body is a particular amount of matter. it can be a solid, liquid or gas. it can be described as existing in a. size and shape. b. motion and force c. time and space. d. location and movement.

Which substance partical has negligible massand travels around outsidethe nucleus