Answer:
a metal spoon left in boiling water
Explanation:
Boiling water is a physical change, because it is changing state of matter, there is a controllable temperature change, and you can change it back.
Frying the egg white is a chemical change, because there is a change of matter, controllable temperature change, but you CAN'T change it back.
Answer:
modern cell theory
Explanation:
theory that cells are the basic structural, functional, and organizational units of both single-celled and multicellular organisms; cells divide and pass on hereditary information; and energy flows within cells.