I would say physical, because a physical change is affecting the form of a chemical substance, but not it's chemical makeup.
Answer:
symbol= F
proton= 9
neutron= 19 I understand this is it ok for you
Answer:
B. an air-conditioning system.
Explanation:
Refrigeration is defined as a process of cooling a system to lower temperature below the surrounding temperature while the removed heat is rejected at higher temperatures.
Heat pumps use the heat output of the refrigeration process, which may also be designed to be reversible, but are otherwise similar to air conditioning units.
