Which elements make up a water molecule?
hydrogen and nitrogen
O oxygen and nitrogen
O oxygen and carbon
hydrogen and oxygen

Hydrogen and Oxygen

Explanation:

also it can be written as H2O

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.

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