At the end of long bones, inside the spinal vertebrae, and inside the flat bones of the pelvis, is a spongy type of bone known as

The correct answer is the cancellous bone. The cancellous bone can be located at the end of the long bones in the body, in the interior of the spinal vertebrae and as well as the flat bones located in the pelvis. The Cancellous bone is a spongy classification of a bone that has an important function. It produces blood cells for the body. 

Mg is used to measure mass