Quiz of the Day
Particle Physics & the Atom
Thursday, 10 September 2026
The Large Hadron Collider fired its first beam on 10 Sep 2008 — exploring atoms, quarks, famous physicists and the building blocks of matter
1. The Large Hadron Collider is operated by which international research organization?
- CERN
- NASA
- MIT
- Fermilab
CERN, the European Organization for Nuclear Research, sits on the border between Switzerland and France near Geneva. Its name comes from the French 'Conseil Européen pour la Recherche Nucléaire'. The World Wide Web was also invented at CERN in 1989 by Tim Berners-Lee.
2. Which subatomic particle carries a negative electric charge?
- Electron
- Neutron
- Proton
- Photon
The electron was the first subatomic particle discovered, identified by J.J. Thomson in 1897. Electrons carry a negative charge and orbit the nucleus of an atom. They are roughly 1,836 times less massive than a proton.
3. The famous particle discovered at the LHC in 2012, associated with how particles get mass, is called the what?
- Higgs boson
- Tau neutrino
- Graviton
- Strange quark
The Higgs boson was discovered at CERN in July 2012, nearly 50 years after it was theorized. It is sometimes nicknamed the 'God particle', a term physicist Peter Higgs disliked. Higgs and François Englert shared the 2013 Nobel Prize in Physics for the theory.
4. Protons and neutrons are made up of even smaller particles called what?
- Leptons
- Quarks
- Bosons
- Muons
Quarks come in six 'flavors': up, down, charm, strange, top, and bottom. A proton is made of two up quarks and one down quark, while a neutron has two down quarks and one up quark. Quarks are never found alone in nature — they are always bound together.
5. Which particle in the nucleus of an atom has no electric charge?
- Neutron
- Proton
- Electron
- Positron
The neutron was discovered by James Chadwick in 1932, earning him the 1935 Nobel Prize in Physics. Neutrons and protons together form the atomic nucleus. A free neutron is unstable and decays in about 15 minutes on average.
6. Which scientist proposed the theory of general relativity and the equation E=mc²?
- Max Planck
- Isaac Newton
- Albert Einstein
- Niels Bohr
Albert Einstein published his equation E=mc² in 1905, part of his 'miracle year' of groundbreaking papers. The equation shows that mass and energy are interchangeable. Einstein won the 1921 Nobel Prize, though it was awarded for the photoelectric effect, not relativity.
7. What is the lightest and most abundant element in the universe?
- Hydrogen
- Carbon
- Oxygen
- Helium
Hydrogen makes up roughly 75% of the normal matter in the universe by mass. Its most common form has just one proton and one electron, with no neutrons. Hydrogen fuels stars like our Sun through nuclear fusion.
8. The LHC accelerates particles around a circular tunnel of approximately what circumference?
- 27 kilometers
- 5 kilometers
- 1 kilometer
- 100 kilometers
The LHC's main ring is about 27 kilometers (17 miles) in circumference, buried around 100 meters underground. Particles travel at 99.9999991% of the speed of light. The tunnel was originally built for an earlier collider called LEP.
9. Which Danish physicist developed an early model of the atom with electrons in fixed energy levels?
- Enrico Fermi
- Niels Bohr
- Werner Heisenberg
- Erwin Schrödinger
Niels Bohr proposed his model of the atom in 1913, with electrons occupying discrete orbits around the nucleus. He won the Nobel Prize in Physics in 1922. The Bohr model was a crucial bridge between classical physics and modern quantum mechanics.
10. The number of protons in an atom's nucleus determines its what?
- Valence
- Atomic number
- Mass number
- Isotope
The atomic number equals the number of protons and defines which element an atom is. Hydrogen has atomic number 1, while gold has 79. Changing the number of protons transforms one element into another entirely.
11. Which family of fundamental particles includes the electron, the muon, and the neutrino?
- Hadrons
- Bosons
- Leptons
- Quarks
Leptons are a class of fundamental particles that do not experience the strong nuclear force. There are six leptons: the electron, muon, tau, and their three corresponding neutrinos. Unlike quarks, leptons can exist in isolation.
12. Marie Curie won Nobel Prizes in which two scientific fields?
- Chemistry and Medicine
- Physics and Economics
- Physics and Medicine
- Physics and Chemistry
Marie Curie won the Nobel Prize in Physics in 1903 and in Chemistry in 1911, for her pioneering research on radioactivity. She remains the only person to win Nobel Prizes in two different sciences. She also coined the term 'radioactivity' and discovered the elements polonium and radium.
13. The strong nuclear force that binds quarks together is carried by which particle?
- W boson
- Gluon
- Graviton
- Photon
Gluons are the force carriers of the strong nuclear force, binding quarks together inside protons and neutrons. Their name comes from 'glue' because they hold matter together. Unlike photons, gluons themselves carry the 'color charge' they mediate.
14. Antimatter particles have the same mass as their normal counterparts but opposite what?
- Size
- Electric charge
- Speed
- Spin direction
The positron, discovered in 1932, is the antimatter counterpart of the electron and carries a positive charge. When matter and antimatter meet, they annihilate, releasing energy. CERN has produced and trapped antihydrogen atoms to study antimatter's properties.
15. Which physicist is credited with discovering the atomic nucleus through his gold foil experiment?
- Ernest Rutherford
- John Dalton
- James Clerk Maxwell
- J.J. Thomson
Ernest Rutherford's gold foil experiment in 1909 revealed that atoms have a tiny, dense, positively charged nucleus. He was surprised that some alpha particles bounced almost straight back, comparing it to firing a shell at tissue paper and having it rebound. Rutherford is often called the father of nuclear physics.