An isotope of any element is the same, with a variation in the neutrons of the nucleus.
The mass number change but the atomic number doesn't.
In this case, protium, deuterium, and tritium are all hydrogen isotopes.
Protium is 1H or Hydrogen-1 is without neutrons.
Deuterium is 2H or Hydrogen-2 has one neutron.
Tritium is 3H or Hydrogen-3 has two neutrons.
Answer: when bright light is present, the pupil reduces in size, or flinching when feeling threatened
Explanation: i know what reflexes are :)
In describing the energy transfer of trophic levels, energy is lost as we move up from a lower level to a higher level. This is because energy is used when for example a primary consumer does body processes before it is eaten by another consumer. hence the lowest trophic level belongs to those which <span>2) has the greatest biomass</span>