Answer:
They are averages.
Explanation:
atomic numbers on periodic tables are derived from the average value of all the isotopes of the element. So being averages they are sometimes not integers.
Answer:
The strength of electric force depends on the amount of electric charge on the particles and the distance between them. Larger charges or shorter distances result in greater force.
Explanation:
The answer is B, the heart is the center of the cardiovascular system as one of its main tasks is to distribute blood throughout the body.
Cell wall:
-acts like a skin
- most selectively controls what is inside and outside of the cell
-rigid
Cell membrane:
-gives a plant cell
-not rigid