Pressure cookers can be thought of as a (closed / open) system. A frying pan is (closed/open)

Question

1 atomic mass unit is the approximate weight of one ______ but is Formerly defined as 1/____ the mass of a neutral _____ atom.

Answer 1

Pressure cookers can be thought of as a closed system. A frying pan is open.
1 atomic mass unit is the approximate weight of one proton or neutron but is formerly defined as 1/12 the mass of a neutral carbon-12 atom.