The planet Earth itself is considered to be a closed system because there is a limit to the amount of matter that is exchanged. However, there are open systems that are ON Earth.
All atoms of the same element have the same
number of protons. Every atom also has a nucleus.
Im pretty sure the answer is <span> 0.01218859659g
not 100% sure tho so please consult someone else b4 answering
i hope this helps!!</span>
B. They work against a strong gravitational force
