JJ Thompson proved Electrons, so negative charge
I would say C is the most correct.
In D it depends on what water source you're using. Let's say it is a waterfall, then the source of the water (melting ice or a lake) may disappear in the future.
If you're using underwater "windmills" placed in the ocean, then you would expect it to last a while as the ocean will not disappear in the near future.
It depends on the concentration of ions which are responsible for the electrical conductivity in aqueous solutions.
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.
Answer:
Answer is given below.
Explanation:
Anode is that electrode where oxidation occurs. Cathode is that electrode where reduction occurs.
In cell representation, half cell present left to salt-bridge notation
is anodic system and another half cell present right to salt-bridge notation is cathodic system.
So anode is Cu and cathode is Ag.
oxidation: 
[reduction: 
]
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chemical equation: 
Oxidizing agent is that species which takes electron from another species. Here 
takes electron from Cu. Hence is the oxidizing agent.
Reducing agent is that species which gives electron to another species. Here Cu gives electron to . Hence Cu is the reducing agent.
