Manganese(II) oxide can react with oxygen to form manganese(IV) oxide as shown below/
2:
2 MnO(s) + O2(g) → 2 MnO2(s)

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When 52.4g of the manganese(II) oxide reacted, 175.9kJ of heat energy was
released. What is the molar enthalpy of reaction for the manganese(II) oxide?
Answer in kJ/mol to one decimal place. You may attach a picture of your work to
support your answer.

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

if it's not useful, feel free to report for mistake in answer.