Isotopes of an element have the same number of and different numbers of .

A. electrons... protons
B. protons... electrons
C. protons... neutrons
D. neutrons... protons

C

Explanation:

Isotopes has the same atomic number which is the same as number of proton but different mass number.

Mass number = proton + neutron A change in the number of neutrons affect the mass number

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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