Answer:
Protons, Electrons, Neutrons
Explanation:
Protons and neutrons are in the center of the atom, making up the nucleus
and...
Electrons surround the nucleus (in cloud or ring form)
Protons: are positively charged
*Protons give the element its name, therefore if there is a change in protons then it is a new element
Electrons: are negatively charged
Neutrons: are neutral and not charged
*Protons and Neutrons give the atom its mass
*If the mass of the same element changes it is because of the neutrons and it called an isotope
There are many models to show you how an atom looks...
Plum Pudding Model, The Nuclear Model (I like to call it the jimmy neutron model because that's what the symbol looks like), Planetary Model, and Quantum Model
*The last two models (Planetary and Quantum) are used more in science class
*The Quantum Model (made by Erwin Schrodinger) is widely accepted and it is the most accurate model since 1926
*The Planetary Model (by Niels Bohr) is used in science class to help you see how electrons are on energy levels and how they move when they are " excited" or absorbs energy and when they lose energy
