Using the periodic table entry below, how many neutrons does the most common isotope of hydrogen have? 1 2 0 cannot be determined

The answer is; 0

The most common hydrogen atom has one (1) proton and one (electron) but no neutron. This hydrogen isotope is referred to as hydrogen-1 or Protium. This hydrogen composes 99.985% of naturally occurring hydrogen atoms. The other atom, Deuterium, has a neutron in its nucleus. The other isotope is Tritium that has two (2) neutrons in its nucleus.

answerscaffolding proteins;

the cell is the smallest structural and functional unit of living organisms, which can exist on its own. therefore, it is sometimes called the building block of life. some organisms, such as bacteria or yeast, are unicellular—consisting only of a single cell—while others, for instance, mammalians, are multicellular.