Final answer:
Hydrogen is unique because the main isotope, protium, can exist without neutrons, which is true. Hydrogen also has isotopes with neutrons such as deuterium and tritium.
Step-by-step explanation:
The main answer to the question about hydrogen's ability to exist without neutrons is True. The most common isotope of hydrogen, also known as protium, consists of only one proton and no neutrons. While hydrogen is unique in this sense, it does have other isotopes with neutrons, such as deuterium (with one neutron) and tritium (with two neutrons). Each isotope of hydrogen exhibits different characteristics and behaviors. It is important to note that while hydrogen can exist without neutrons, other elements on the periodic table have isotopes with varying numbers of neutrons, making each element unique in its neutron-proton ratios.