The answer is (3) An electron in the third shell has more energy than an electron in the second shell. The energy of electron will increase when number of shell increase.
Answer:

Explanation:
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In this case, since the enthalpy change for any process is computed by subtracting the enthalpy of the final state and the enthalpy of the initial state, for the given phase change, we subtract the enthalpy of the liquid (final state) and the enthalpy of the solid (initial state) considering this a melting process:

Which makes sense because this process absorbs energy.
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Answer:
From primary consumer to secondary consumer; that is the answer!
we can do soo by noticing any colour change, or by the formation of an insoluble precipitate or by the evolution of a gas.