The Conservation of matter states that matter can't be created or destroyed in closed systems, what about open

Question

I believe in a open system, that law wouldn't work, the law specificly says in a closed system. This is for a debate for my school, im debateing the topic, "can matter be created or destroyed" negative and positive, any help would be appreciated. (sources needed please, thanks)

Answer 1

With an open system anything goes! That is, if an unspecified amount of matter or energy can "flow" in or out of a system then it is impossible to keep tags on the energy or mass balance, very much as you cannot keep tags on your expenses if you loose money out of your pocket.:-)

Answer 2

Recognize that "Conservation of matter" also ignores fission
and fusion.

In those cases, matter is exchanged for energy and visa versa.

E=mc^2

Thank Albert Einstein.