Every atom is built from three kinds of particles: protons, neutrons and electrons. Two of them, the protons and neutrons, sit packed in a tiny central core, while the electrons move around the outside of it. Only the electron is truly basic. Protons and neutrons are made of still smaller pieces, so “three types” describes the parts of an atom, not everything physicists know about.1Wikipedia. Subatomic particle
Charge, Mass and Location of Each Particle
- Proton: charge +1, mass about 1 atomic mass unit (amu), found in the nucleus.2LibreTexts. What Are the 3 Types of Subatomic Particles
- Neutron: no charge, mass slightly more than 1 amu, found in the nucleus.3LibreTexts. What Are the 3 Types of Subatomic Particles
- Electron: charge −1, mass close to 0 amu, found outside the nucleus.4LibreTexts. What Are the 3 Types of Subatomic Particles
The nucleus is the tiny, positively charged center of the atom.5Journal of Chemical Education. The Discovery of the Electron, Proton, and Neutron An electron’s charge is exactly as strong as a proton’s, just opposite in sign.6LibreTexts. What Are the 3 Types of Subatomic Particles
Mass is where they split apart. A proton is about 1,836 times heavier than an electron.7Vaia. What Are the 3 Types of Subatomic Particles? So electrons add almost nothing to an atom’s weight, and nearly all of it sits in the nucleus.8LibreTexts. What Are the 3 Types of Subatomic Particles
On a periodic table, an atom’s mass in amu is roughly its protons plus its neutrons. Electrons are usually left out of the count because they are so light.
It’s easy to confuse a neutron with a neutral atom. A neutron is a single particle with no charge. A neutral atom is one with equal numbers of protons and electrons, whose charges cancel out. An atom can be neutral overall and still contain plenty of charged particles.
What Protons Do
The number of protons in a nucleus is called the atomic number.9Wikipedia. Atomic number Each element has its own, from 1 for hydrogen to 92 for uranium among natural elements.10Wikipedia. Atomic number An atom with 6 protons is always carbon, and adding a proton would make it a different element. Two atoms can have different masses and still be the same element, because mass depends on neutrons too. The proton count is also the main thing that sets how an element behaves chemically.11LibreTexts Chemistry. What Are the 3 Types of Subatomic Particles In an uncharged atom, the number of electrons equals the number of protons.12Wikipedia. Atomic number
Changing the electron count does something different. An atom that loses or gains electrons becomes an ion, not a new element. If it loses an electron, it becomes positively charged. It stays the same element because its protons are unchanged.
What Neutrons Do
Protons and neutrons are bound together by a force called the strong force.13Wikipedia. Isotope Neutrons add attraction without adding any electrical push.14Wikipedia. Isotope They sit between protons and spread them slightly apart, easing the repulsion.15Wikipedia. Isotope That is why two or more protons can’t stay together in a nucleus without at least one neutron.16Wikipedia. Isotope Hydrogen’s most common form is a special case: it has one proton and no neutrons, because a single proton has no other proton to repel.
The strong force is far stronger than electric repulsion, but it only works over extremely short distances, about the size of a nucleus. A proton feels the strong pull only from its nearest neighbors, while its electric push reaches across the whole nucleus. In a very large nucleus, the push adds up across many protons while the pull stays local, which is why big nuclei are harder to hold together.
The more protons a nucleus has, the more neutrons it needs per proton to stay stable.17University of Texas at Austin Department of Chemistry. What Are the 3 Types of Subatomic Particles? Stable iron has 26 protons and 30 neutrons.18Chemistry Fundamentals. Nuclear Chemistry Stable lead-207 has 82 protons and 125 neutrons, about 1.5 neutrons per proton.19Chemistry Fundamentals. Nuclear Chemistry
Varying the neutron count produces isotopes: atoms of one element with different numbers of neutrons. They have the same number of protons, so they are the same element. The number in a name like carbon-14 is protons plus neutrons. Isotopes behave alike chemically but differ in weight.
Some isotopes are radioactive. A nucleus with the wrong neutron balance can be unstable, and it eventually changes to reach a steadier mix. That change is what we call radioactive decay.
Past lead, adding more neutrons no longer fixes the problem, so every nucleus with more protons than lead is unstable and eventually decays. Uranium, the heaviest natural element, is radioactive for this reason, and its nuclei slowly change into lighter ones.
What Electrons Do
Electrons are held near the nucleus by the attraction between opposite charges. They fill energy levels, often drawn as shells around the nucleus.20BYJUS. What Are the 3 Types of Subatomic Particles An orbital describes where an electron is most likely to be, rather than a fixed path.21Florida State University. Orbitals and Bonds The shell drawing is still useful for counting how many electrons sit at each level. Electrons can also break free and exist on their own, not tied to any atom.22BYJUS. What Are the 3 Types of Subatomic Particles
When atoms form a bond, their orbitals combine.23Florida State University. Orbitals and Bonds Electrons are what join atoms into molecules.
Many everyday things come down to electrons. A static shock is electrons moving between surfaces. Metals conduct electricity because some of their electrons move freely.
How the Three Particles Were Discovered
Michael Faraday suggested in 1834 that electricity came in fixed units.24Journal of Chemical Education. The Discovery of the Electron, Proton, and Neutron George Stoney gave the unit of charge the name “electron” in 1891.25Journal of Chemical Education. The Discovery of the Electron, Proton, and Neutron Ernest Rutherford showed in 1911 that atoms have a tiny positive nucleus.26Journal of Chemical Education. The Discovery of the Electron, Proton, and Neutron By 1917 he had shown that the hydrogen nucleus, the proton, exists in all other nuclei.27BYJUS. What Are the 3 Types of Subatomic Particles James Chadwick identified the neutron in 1932.28BYJUS. What Are the 3 Types of Subatomic Particles He explained odd radiation as particles about as heavy as protons with no charge.29Journal of Chemical Education. The Discovery of the Electron, Proton, and Neutron
Rutherford revealed the nucleus by firing particles at thin gold foil. Most passed straight through, but a few bounced back sharply. That meant mass and charge sat in a tiny center.
The proton was hard to pin to a date. Hydrogen is the lightest atom, and its nucleus is a single positive particle, so the idea of a basic positive particle grew from studying hydrogen. Rutherford’s 1917 result went further: the same hydrogen nucleus turns up inside other elements’ nuclei, which made it a building block rather than just hydrogen’s core. That is why the proton is credited to his work over several years rather than a single moment.
The neutron came last because it has no charge. Electric fields don’t push or pull it, so it leaves no easy trace. It had to be found through what it knocked loose.
Are There Smaller Particles
Particles are either elementary, with nothing smaller inside, or composite, built from smaller ones.30Wikipedia. Subatomic particle The electron is elementary.31Wikipedia. Subatomic particle Protons and neutrons are composite, made of quarks and gluons.32PubMed. Modified structure of protons and neutrons in correlated pairs Physicists group the basic matter particles into quarks and leptons, six of each.33CERN. The Standard Model The electron is one of six leptons, alongside heavier cousins and neutrinos.34Space. Leptons: The elementary particles explained Forces are carried by separate particles, such as the photon for electromagnetism and gluons for the strong force.35Energy.gov. DOE Explains…Bosons and Fermions
The six leptons are the electron, the muon, a heavier particle called the tau, and three kinds of neutrino. The families differ in which forces act on them: quarks feel the strong force, while leptons such as the electron do not.
The charges from earlier come from quarks. Up quarks carry +2/3 charge and down quarks −1/3. Two ups and a down give a proton’s +1, while one up and two downs add to 0 for a neutron.
All stable matter is made from the lightest group: up quarks, down quarks and electrons.36CERN. The Standard Model That’s because heavier particles quickly decay into lighter ones.37CERN. The Standard Model A muon is about 207 times heavier than an electron and soon decays into one.38Space. Leptons: The elementary particles explained Heavier quarks likewise exist but decay quickly, so they show up only in high-energy collisions or cosmic rays. They don’t last long enough to build atoms.
School still says three because, for chemistry and atoms, three particles explain everything you’ll meet. Quarks never appear on their own in nature. The deeper list matters for physics, not for reading a periodic table.
Can One Particle Turn Into Another
In one kind of radioactive decay, a neutron inside a nucleus turns into a proton.39Energy.gov. DOE Explains…Beta Decay The nucleus gives off an electron and an antineutrino.40Energy.gov. DOE Explains…Beta Decay This happens because a down quark in the neutron changes into an up quark.41Wikipedia. Beta decay The atom gains a proton and becomes a different element.
The emitted electron is a new particle created in the process, not one that was sitting inside the nucleus beforehand. The proton count goes up by one while the total number of protons and neutrons stays the same, so the mass number is unchanged. Carbon-14 becoming nitrogen-14 is an example.
This happens only in some nuclei. It occurs when the mix of neutrons and protons is unbalanced, and the change moves the nucleus toward a steadier mix. A neutron on its own, outside a nucleus, also decays this way, while neutrons inside stable nuclei do not.
Every matter particle has an antiparticle with the same mass but opposite charge.42home.cern. Antimatter The electron’s twin, the positron, is positive. When a particle meets its antiparticle, both vanish, leaving energy, mostly as light.43home.cern. Antimatter
You meet all this in real life. Radioactive carbon-14 decays the way described above, which is the basis of carbon dating. PET scans in hospitals detect light from positrons meeting electrons. Proton beams are also used to treat some cancers.