The number of protons in an atom determines the identity of the element.
See these two related questions for more information:
[http://wiki.answers.com/Q/What_is_the_atomic_number_and_what_does_it_tell_you_about_the_number_of_protons_in_an_atom
What is the atomic number and what does it tell you about the number of protons in an atom?]
and
[http://wiki.answers.com/Q/How_do_you_find_the_number_of_protons_and_electrons_and_neutrons_in_an_atom
How do you find the number of protons and electrons and neutrons in an atom?]
The distinguishing subatomic particle of an atom is its proton(s). The atomic number (amu) of an element is equal to the number of protons it has. Therefore if you know the number of protons in a given atom you can identify which element this atom is. Electrons and nuetrons can vary and give you isotopes and ions so they cannot be used as distinguishing factors.
The number of protons distinguish the atoms of one element from those of another element.
The number of protons determines what is the element.
Electrons
Protons, electrons and neutrons
The electron shell is the source of an element's chemical properties and the moderator of chemical reactions; the electron shell depends on the protons that constitute the atom
The number of protons is unique for every element.Varying the number of neutrons will give you an isotope of the same element.Varying the number of electrons will give you an ion of the same element.
An "element" is not a subatomic particle. Your question makes no sense and is therefore unanswerable.Another answer:Since an element is not a subatomic particle, the only answer can be a proton.
Neutron
Silicon is a chemical element not a particle.
This particle is the proton.
Atom is a chemical element, not a particle.
element
Nitrogen is a chemical element not a particle.
This particle is the proton, equal to the atomic number.
Proton
No, it is an element - a type of atom. The positive hydrogen ion, on the other hand, is usually identical with the proton, which is a subatomic particle.
The number of protons defines the element.
The number of protons determines what is the element.