6.4 - Nuclear and Particle Physics

Question 1

What is the Unified Atomic Mass Unit?

Answer 1

1/12 of the mass of a carbon-12 atom. 1u = 1.661 x 10^-27kg

Question 2

What is the Proton Number?

Answer 2

The number of protons inside the nucleus of a particular atom. Also known as the atomic number

Question 3

What is the Nucleon Number?

Answer 3

The number of nucleons (protons and neutrons) inside the nucleus of a particular atom. Also known as the Mass Number

Question 4

What is an Isotope?

Answer 4

Atoms of the same element which contain the same number of protons but can have varying numbers of neutrons

Question 5

What is the Strong Nuclear Force?

Answer 5

A force that acts between nucleons and holds the nucleus together against the electrostatic repulsion of the protons

Question 6

What are Fundamental Particles?

Answer 6

Particles that Connor be broken down into smaller components

Question 7

What are Hadrons?

Answer 7

Particles consisting of a combination of quarks to give a net zero or whole number charge. Neutrons and protons are hadrons

Question 8

What are Leptons?

Answer 8

Fundamental particles. Electrons and neutrinos are Leptons

Question 9

What are Quarks?

Answer 9

Components of hadrons, and have a fractional electric charge. They are believed to be fundamental particles

Question 10

What is a Neutrino?

Answer 10

A fundamental particle (lepton) with almost no mass and zero charge. Each neutrino has an antimatter partner, called an antineutrino

Question 11

What is the Weak Nuclear Force?

Answer 11

A force felt by both quarks and leptons. It can change quarks from one type to another or leptons from one type to another and is responsible for beta decay

Question 12

What is an Antiparticle?

Answer 12

A particle of antimatter that has the same rest mass but (if charged) the equal and opposite charge to its corresponding particles

Question 13

What is an Alpha Particle?

Answer 13

A particle comprising two protons and two neutrons ejected from the nucleus during radioactive decay. It is identical to a helium nucleus and is emitted due to its unusually high stability as a particle

Question 14

What is a Beta Particle?

Answer 14

A high speed electron emitted from the nucleus during beta decay. It is produced when a neutron changes into a proton

Question 15

What is a Gamma Ray?

Answer 15

A form of electromagnetic wave with wavelengths between 10^-16 and 10^-9m. Emitted from the nucleus during gamma decay

Question 16

What is Beta-Minus decay?

Answer 16

When a neutron breaks down into a proton under the influence of the weak nuclear force, and a beta-minus particle and antineutrino are emitted. A beta-minus particle is an electron

Question 17

What is Beta-Plus decay?

Answer 17

When a proton in the nucleus break down into a neutron under the influence of the weak nuclear force, and a beta-plus particle and neutrino are emitted. A beta-plus particle is a positron

Question 18

What is Activity?

Answer 18

The number of nuclear decays (the number of gamma rays emitted) per unit time. An activity of one decay per second is called one becquerel (Bq)

Question 19

What is the Decay Constant?

Answer 19

The probability that an individual nucleus will decay per unit time. Given by lambda = A/N where A is activity and N is number of undeclared nuclei

Question 20

What is Half Life?

Answer 20

The mean time taken for the activity of a source, or the number of undeclared nuclei present, to halve

Question 21

What is Carbon Dating?

Answer 21

A technique used to determine the age of organic matter from the relative proportions of the carbon-12 and carbon-14 isotopes that it contains, using the half life of carbon-14

Question 22

What is Annihilation?

Answer 22

The process in which a particle and its antiparticle interact and their combined mass is converted to energy via E=mc^2

Question 23

What is Pair Production?

Answer 23

The process of creating a particle-antiparticle pair from a high-energy photon

Question 24

What is Mass Defect?

Answer 24

The difference in mass between the mass of a nucleus and the total mass of its separate nucleons

Question 25

What is Binding Energy?

Answer 25

The minimum energy required to separate the nucleus into its constituent parts

Question 26

What is Induced Nuclear Fission?

Answer 26

It occurs when a nucleus absorbs slow-moving neutrons and the resulting unstable nucleus undergoes a fission reaction to split into two smaller nuclei and a small number of neutrons, releasing energy

Question 27

What is a Chain Reaction?

Answer 27

The sequence of nuclear reactions produced when an induced nuclear fission reaction triggers more than one further fission reaction

Question 28

What is a Control Rod?

Answer 28

A rod that can be lowered into the core of a nuclear reactor, absorb neutrons and slow he chain reaction. Control rods are usually made of boron

Question 29

What is a Moderator?

Answer 29

A substance used in a nuclear reactor which slows down neutrons so that they have a greater chance of being absorbed by the fissile nuclear fuel. They are usually made of graphite