protons
The number of protons, which is the atomic number of an element, determines the identity of an element.
Assuming that you mean the chemical properties, the electrons are what define each element. If you meant subatomic particles, then it doesn't matter; each subatomic particle has unique characteristics.
no i cant answer it
Every subatomic particle has mass, so every particle will cause a slight mass change. However, in an isotope, the mass change between the parent and daughter is caused by a change in the number of neutrons.
The smallest particle in gold should in fact be gold. Gold is an element, Au, and thus should only contain gold atoms. You could also argue that some subatomic particle is the smallest particle in gold.
This particle is the proton.
The identity of a chemical element is given by the number protons.
The number of protons is determining the element
Electrons
There is no individual sub-atomic particle that is responsible for the identity of an element. It is the way the electrons, protons and (neutrons) are arranged in an element that gives it it's identity.
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.
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.