The element with an atomic mass of 215 ami, and 110 neutrons: (G1) U (H3) NIUM

c is the answer because when something is left after something evaporates that shows the chemical change.

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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