1.1 Matter

Question 1

matter

Answer 1

any substance that has mass and takes up space by having volume.

Question 2

spacetime

Answer 2

any mathematical model which fuses the three dimensions of space and the one dimension of time into a single four-dimensional manifold.

Question 3

atom

Answer 3

smallest unit into which matter can be divided without the release of electrically charged particles. it also is the smallest unit of matter that has the characteristic properties of a chemical element.

Question 4

nucleus

Answer 4

the massive, positively charged central part of an atom, made up of protons and neutrons.

Question 5

electron cloud

Answer 5

​the region of negative charge surrounding an atomic nucleus that is associated with an atomic orbital. high probability of containing electrons.

Question 6

electron

Answer 6

a negatively charged subatomic particle; can be either free or bound to the nucleus of an atom.

Question 7

elementary particle

Answer 7

the smallest known building blocks of the universe; thought to have no internal structure / zero-dimensional points that take up no space.

Question 8

lepton

Answer 8

any member of a class of subatomic particles that respond only to the electromagnetic force, weak force, and gravitational force and are not affected by the strong force.

Question 9

electromagnetic force

Answer 9

aka Lorentz force; explains how moving and stationary charged particles interact. every charged particle gives off an electric field, whether or not it’s moving. moving charged particles (like those in electric current) give off magnetic fields.

Question 10

proton

Answer 10

made of two up quarks and one down quark; stable subatomic particle that has a positive charge equal in magnitude to a unit of electron charge and rest mass.

Question 11

neutron

Answer 11

made of two down quarks and one up quark; an uncharged elementary particle that has a mass nearly equal to that of the proton and is present in all known atomic nuclei except the hydrogen nucleus.

Question 12

nuclear force / strong force

Answer 12

binds quarks together in clusters to make more-familiar subatomic particles, such as protons and neutrons; also holds together the atomic nucleus and underlies interactions between all particles containing quarks.

Question 13

quark

Answer 13

any of several elementary particles that are postulated to come in pairs (up and down) of similar mass with one member having a charge of +²/₃ and the other a charge of −¹/₃ and are held to make up hadrons.

Question 14

dark matter

Answer 14

composed of particles that do not absorb, reflect, or emit light, so they cannot be detected by observing electromagnetic radiation; material that cannot be seen directly. may account for the unexplained motions of stars within galaxies.

Question 15

dark energy

Answer 15

the mysterious force that’s causing the rate of expansion of our universe to accelerate over time, rather than to slow down.

Question 16

families

Answer 16

organizes leptons and quarks according to properties.

Question 17

generations

Answer 17

organizes leptons and quarks according to mass.

Question 18

fermions

Answer 18

a subatomic particle, such as a nucleon, which has half-integral spin and follows the statistical description given by Fermi and Dirac.

Question 19

mass in GeV/c^2

Answer 19

Giga-Electron-Volts divided by the speed of light squared. electron-volts is a measure of energy and is the energy gained by an electron crossing a potential of one volt.

Question 20

flavors

Answer 20

the six types of quarks: up, down, charm, strange, top, and bottom.

Question 21

electron neutrino

Answer 21

lightest neutrino; net zero electric charge; part of 1st generation.

Question 22

muon neutrino

Answer 22

middle neutrino; net zero electric charge; part of 2nd generation.

Question 23

tau neutrino

Answer 23

heaviest neutrino; net zero electric charge; part of 3rd generation.

Question 24

up and down quarks

Answer 24

lowest masses of all quarks; generally stable; most common; usually come from heavier quarks through particle decay.

Question 25

subatomic / elementary particle

Answer 25

any of various self-contained units of matter or energy that are the fundamental constituents of all matter.

Question 26

protons and neutrons

Answer 26

contain quarks bound together.

Question 27

gravitational force

Answer 27

the universal force of attraction acting between all matter; weakest.

Question 28

weak force

Answer 28

fundamental force that acts between leptons and is involved in the decay of hadrons. responsible for nuclear beta decay (by changing the flavor of quarks) and for neutrino absorption and emission.

Question 29

fundamental forces

Answer 29

weak, strong / nuclear, gravitational, electromagnetic.

Question 30

spin

Answer 30

intrinsic form of angular momentum carried by elementary particles, composite particles (hadrons), and atomic nuclei.

Question 31

intrinsic properties of particles

Answer 31

independent of how much of a material is present and is independent of the form of the material; dependent mainly on the fundamental chemical composition and structure of the material.

Question 32

the major intrinsic properties

Answer 32

electric charge, color, elasticity, melting, boiling, and freezing points, etc.

Question 33

extrinsic properties of particles

Answer 33

not essential or inherent to the subject that is being characterized; dependent on amount of matter present.

Question 34

the major extrinsic properties

Answer 34

mass, weight, volume, length, etc.

Question 35

strange quark

Answer 35

3rd lightest of all quarks; found in hadrons; decays into up quark.

Question 36

charm quark

Answer 36

3rd most massive of all quarks; found in hadrons; decays into strange quark (95%) or down quark (5%).

Question 37

top quark

Answer 37

the most massive of all quarks; couples to the Higgs Boson; decays into bottom quark (99.8%), strange quark (0.17%), or down quark (0.007%).

Question 38

bottom quark / beauty quark

Answer 38

3rd generation heavy quark; low rate of transition to lower mass quarks; decays into charm quark or up quark.

Question 39

up quark

Answer 39

lightest of all quarks; helps form protons and neutrons; stable; if decays, decays into down quark + positron + electron neutrino.

Question 40

down quark

Answer 40

second lightest of all quarks; helps form protons and neutrons; stable; if decays, decays into up quark + electron + electron antineutrino.

Question 41

antiquark

Answer 41

differs from the quark only in that some of its properties, such as charge has equal magnitude but opposite sign.

Question 42

colour (physics)

Answer 42

source of the strong force. particles without this source do not “feel” the strong force; particles with this force, principally the quarks, do “feel” the strong force.

Question 43

neutrino

Answer 43

least massive of the known elementary particles, with the exception of those thought to be completely massless, such as the photon; only interact with weak force and gravity (2/4 known forces).

Question 44

fermions

Answer 44

category of elementary particles: matter; divided into quarks and leptons; very small and light.

Question 45

photon

Answer 45

the smallest discrete amount or quantum of electromagnetic radiation; the basic unit of all light. always in motion and, in a vacuum, travel at a constant speed, the speed of light, denoted by the letter c.

Question 46

gluon

Answer 46

an elementary particle that acts as the exchange particle for the strong force between quarks. analogous to the exchange of photons in the electromagnetic force between two charged particles. they put quarks together forming hadrons such as protons and neutrons.

Question 47

gluon

Answer 47

an elementary particle that acts as the exchange particle for the strong force between quarks. analogous to the exchange of photons in the electromagnetic force between two charged particles. they put quarks together forming hadrons such as protons and neutrons.

Question 48

meson

Answer 48

hadronic subatomic particles composed of an equal number of quarks and antiquarks, usually one of each, bound together by strong interactions. have a meaningful physical size, a diameter of roughly one femtometer, which is about 0.6 times the size of a proton or neutron.

Question 49

antiquark

Answer 49

the antimatter partners of quarks; they have the same masses as quarks, but all of the other properties are reversed. when a quark meets this, they may annihilate, disappearing to give some other form of energy

Question 50

antiquark

Answer 50

the antimatter partners of quarks; they have the same masses as quarks, but all of the other properties are reversed. when a quark meets this, they may annihilate, disappearing to give some other form of energy.

Question 51

antilepton

Answer 51

the antimatter partners of leptons; have the same masses as leptons, but all of the other properties are reversed. when a lepton meets this, they may annihilate, disappearing to give some other form of energy.

Question 52

antimatter

Answer 52

matter with the same masses but opposite charges.

Question 53

alpha decay

Answer 53

type of radioactive decay in which an atomic nucleus emits an alpha particle (helium nucleus) and thereby transforms or ‘decays’ into a different atomic nucleus, with a mass number that is reduced by four and an atomic number that is reduced by two.

Question 54

beta decay

Answer 54

type of radioactive decay in which a beta particle (fast energetic electron or positron) is emitted from an atomic nucleus, transforming the original nuclide to an isobar of that nuclide.

Question 55

gamma decay

Answer 55

type of radioactive decay in which no particles are ejected from the nucleus when it undergoes this type of decay. Instead, a high energy form of electromagnetic radiation - a gamma ray photon - is released.

Question 56

baryons

Answer 56

a type of composite subatomic particle which contains an odd number of valence quarks (at least 3). belong to the hadron family of particles (composed of quarks). also classified as fermions because they have half-integer spin.