Quite Small, Those Subatomic Particles Quiz

Answer: Up and down

The up quark has a positive electric charge equal to 2/3 of that of an electron, while the down quark has a negative electric charge of 1/3 of that of an electron. A particle composed of two up quarks and one down quark would thus have an electric charge of +1 (a proton), while the combination of one up quark and two down quarks has a neutral electric charge (a neutron).

In 1964, the existence of the up quark and the down quark was predicted. It took four years before experiments at Stanford University gave sufficient proof of the up quark: deflection of light particles showed that a proton consists of three elementary particles.

Top and bottom quarks are another pair of quarks, predicted in 1973. They are known as the third generation of quarks. The bottom quark was discovered in 1977, while the top quark (a very massive one) was only demonstrated in 1995.
The other two quarks (the second generation) are the strange quark and the charm quark.

Left, right, in and out have never been used as names for quarks. These names are pure figments of my imagination.

Answer: Joseph John Thomson

The British scientist J.J. Thomson is the one we were looking for. His experiment showed the existence of small, negative charged particles in each atom. Thomson then designed a (now obsolete) "plum pudding" model of the atom: a large sphere in which some negatively charged particles are randomly dispersed.

Hans Geiger (after whom the Geiger counter was named) discovered a major deflection of some alpha rays, caused by the presence of positive particles in the atomic nucleus. Frederick Soddy discovered the existence of isotopes: atoms with different numbers of neutral particles. Lise Meitner was one of the scientists in the team that discovered nuclear fission. Only the team leader, Otto Hahn, received a Nobel prize for this discovery.

Answer: Gluon

Most atomic models indicate a number of protons (massive particles with a positive electric charge), the same number of electrons (very small particles with a negative electric charge) and a number of neutrons (massive particles without electric charge), where in most instances the number of neutrons exceeds the number of protons.

Atomic models are based upon non-ionized atoms. An atom is ionized when its number of electrons differs from its number of protons, so the atom would have an electric charge. Ions explain chemical bonds.

The protons and the neutrons are found in the nucleus of the atom, while the electrons orbit the nucleus at high speed.

Gluons are subatomic particles without any mass, which "glue" together various other subatomic particles.

Answer: Alpha

Alpha was already used for one of the three similarly known forms of radiation: alpha, beta and gamma radiation. Radiation is (to put it simply) the travel of electromagnetic waves. Alpha radiation concerns waves containing helium nuclei (two protons and two neutrons), beta radiation is the term for waves containing separate electrons, and gamma radiation consists of waves of photons.

The pion (named after the Greek letter pi) is a subatomic particle consisting of one quark of the first generation (up quark or down quark) and one anti-quark of the same generation. It may carry positive or negative electric charge.

The muon and the tau are subatomic particles similar to the electron, but they are unstable (whereas an electron does not decay). The muon is larger than the electron, and the tau is larger than the muon.

Answer: True

Subatomic particles and their anti-particles are doomed to annihilate each other when coming into contact (read: at a sufficiently near position). As our universe is completely made of the ordinary subatomic particles, anti-particles can only exist for an infinitesimal time in our universe. An anti-particle is roughly the equivalent of any subatomic particle (same mass, same spin), but with reversed electric charge. So the anti-proton is electrically negative, and the positron (anti-electron) has a positive electric charge.

Some neutral subatomic particles have specific anti-particles (for instance the neutron and the anti-neutron), while others are their own anti-particles (for instance the photons).

Answer: Francois Englert

Three different publications in 1964 predicted the existence of what later would be called the Higgs boson: one by the British scientist Peter Higgs, one by the two Belgian scientists François Englert and Robert Brout, and one by the British Kibble and his American colleagues Guralnik and Hagen.

In 2012 the CERN finally discovered a particle which is identified as the Higgs boson. The year after, Higgs and Englert were awarded the Nobel prize. Robert Brout was already deceased at that time, so he could not be nominated.

I haven't found any reason why the Nobel committee did not reward Guralnik, Hagen and Kibble. Perhaps the reason was that Guralnik, Hagen and Kibble had chosen a fundamentally different title for their paper, entitled "Global Conservation Laws and Massless Particles".

Englert and Brout published "Broken Symmetry and the Mass of Gauge Vector Mesons", while Higgs's title was similarly titled "Broken Symmetry and the Masses of Gauge Bosons".

Answer: Strong interaction

The strong interaction is a very intense force that operates only on a scale of some thousandths of an atom. Remember the scale of an atom: one millimetre can concatenate 2 to 16 million atoms (an atom typically measured as 62 to 520 picometres, and one millimetre equals 1,000 million picometres). The strong interaction only operates in femtometres, and a femtometre is one thousandth of a picometre.

Quarks and gluons have a colour charge. This "colour" charge has nothing to do with the visual spectrum: the scale is so small that scientists can only observe indirect consequences of the interactions between individual quarks and gluons.
There were three possible states calculated for the quarks, so scientists named these three possible states "red", "green" and "blue". Antiquarks also have three possible states: anti-red (symbolised by cyan), anti-green (symbolised by magenta) and anti-blue (symbolised by yellow).

When three quarks combine to form a baryon (for instance a proton or a neutron), each of the different colour states must be present, so the composite particle has no colour charge.

Likewise, combining a quark with an antiquark to obtain a meson, has to use one colour and its anti-colour, so the result is once again white (without colour charge).

Gravitation has to do with mass, and the electromagnetic force is based upon the electric charge. The weak interaction changes the type of quarks in a process of radioactive decay.

Answer: Hadron

The CERN (originally Conseil Européen de Recherche Nucléaire, translated to European Council for Nuclear Research) is based in Switzerland. Although the name changed to "Organisation Européenne de Recherche Nucléaire", the abbreviation was maintained.

CERN operates a number of particle accelerators in their underground establishment in the western part of Switzerland (near Geneva) stretching to, and a bit beyond, the French border. The Large Hadron Collider was completed in 2008, and is a roughly elliptical tunnel of over 27 km in circumference. The tunnel is, of course, equipped with multiple measurement systems that communicate their findings to a computer network of over 140 supercomputers in at least 35 countries.

The incorrect answers are chemical elements with symbols that also start with H: Hydrogen (H), Helium (He) and Mercury (Hg) - in its obsolete denomination Hydrargyrum.

Answer: Satyendra Nath Bose

Satyendra Nath Bose (1894-1974) was an Indian scientist, best known for his mathematical equations in quantum physics. Bosons are the particles with integer spins, including the photon, the gluons and the Higgs boson, as well as the composite particles composed of an even number of elementary particles (the mesons, but also theoretical particles such as the tetraquark or the graviton). More than one boson with the same characteristics (mass, spin, electric charge...) can occupy the same space at the same time.

The other class of subatomic particles, besides the bosons, is the fermions (named after Enrico Fermi), having half spin (for instance 3/2 spin). Fermions are mutually exclusive if they have exactly the same characteristics.

The incorrect answers all have used a nickname or alias more or less resembling Bose's surname. Bruce Springsteen is nicknamed the Boss, Charles Dickens signed some of his correspondence with the alias Boz, and Dan Blocker played the role of Hoss (Cartwright) in the TV series "Bonanza". None of those have ever meddled with the science of subatomic particles.

Answer: Photon

The photon is the only of these subatomic particles of which the existence is already proved beyond any reasonable doubt. All the red herrings (aka alternate answers) are hypothetical.

The photon has no mass nor electric charge. It is a stable particle emitted in various processes: radioactive decay, annihilation of matter with antimatter, artificial particle acceleration... The photon travels at extremely high speed: when it occurs in a vacuum, it will travel at the speed of light.
Photons carry the electromagnetic force. As they have no mass, their interactions can operate at long distance.

The hypothetical graviton would be an elementary subatomic particle that carries the gravitation force. The hypothetical dilaton would explain quantum physics in a universe having more than the usual four dimensions (length, width, height and time). The hypothetical tachyon would move faster than the speed of light.