The mass of an item is contained primarily in its _ ?

Aflame cell is at the end of each tubule of the nephridium malpighian tubules kidneys none of the above

You are working in the lab and are working with the same element but with varying isotopes of the element. you are working with c-11, c-13, c-14, and c-15. what is the average atomic mass of this element? (use periodic table) a- 12 b-15 c-14 d-13

What are the student's observations and inferences before he starts his investigation?