<span>B. 51 50
Z and Z
25 25
It is because only this element have equal number of Protons (Bottom number) and are different in atomic masses (upper number)
Hope this helps!</span>
C, it prevents the Earth from ultraviolet radiation and other harmful substances from space
Answer:
c.) increase the concentration of one of the solutions
Explanation:
Propylethylene would be the answer
