An electron has nearly no discernible mass. A proton has a mass of 1 atomic mass unit (AMU) as does a neutron. According to the Periodic Table of Elements an atom of hydrogen has a mass on average of 1AMU (1.007) since the most common isotope of hydrogen has no neutrons and is a single proton.
Which type of plant species would a botanist be LEAST interested in studying for this purpose? A plant species