Memory definitions

Question 1

Nuclear model

Answer 1

This model describes the atom as having a small positively charged core surrounded by negatively charged particles called electrons

Question 2

Mass defect

Answer 2

The difference between the mass of an intact nucleus and the sum of the masses of the individual nucleons of which it is made

Question 3

Strong nuclear force

Answer 3

One of the four fundamental forces; the strong nuclear force acts over small distances in the nucleus to hold the nucleons together against the repulsive electrostatic forces exerted between the protons.

Question 4

Binding energy

Answer 4

The mechanical work that must be done against the forces holding a nucleus together to disassemble it into component parts.

Question 5

Natural radioactive decay

Answer 5

the process by which the nucleus of an unstable atom loses energy by emitting radiation, including alpha particles, beta particles, gamma rays and electrons without artificial stimulus to do so.

Question 6

Radiation

Answer 6

the emission of energy as electromagnetic waves or as moving subatomic particles, especially high-energy particles, which cause ionisation.

Question 7

Ionisation

Answer 7

The process by which an atom or molecule acquires a negative or positive charge by gaining or losing electrons.

Question 8

Alpha radiation

Answer 8

The composite particle consisting of two protons and two neutrons tightly bounded together; emitted from the nucleus of some radionuclides.

Question 9

Beta negative radiation

Answer 9

A type of radioactive decay in wh8ich an energetic electron and associated antineutrino are emitted from an atomic nucleus.

Question 10

Beta positive decay

Answer 10

A type of radioactive decay in which an energetic positron and associated neutrino are emitted from the nucleus.

Question 11

Gamma radiation

Answer 11

Extremely high frequency electromagnetic radiation (high frequency photons) emitted form the nucleus of some radionuclides.

Question 12

Nuclear fusion

Answer 12

A nuclear reaction in which two or more atomic nuclei combine to form one or more different, heavier atomic nuclei and subatomic particles

Question 13

Nuclear fission

Answer 13

The process in which a large unstable nucleus splits, forming two (or more) smaller more stable nuclei and releasing neutrons and energy.

Question 14

Artificial transmutation

Answer 14

The process in which an isotope is intentionally caused to change by nuclear processes into an isotope of another element (distinct from natural radioactivity).

Question 15

Half life

Answer 15

the time taken for half of the atoms in a sample of the material to undergo radioactive decay

Question 16

Electric charge

Answer 16

a physical property of an object that causes it to experience a force when placed in an electric field.

Question 17

Law of Conservation of electric charge

Answer 17

The total electric charge of an isolated system remains constant, regardless of charges within the system.

Question 18

Law of Electrostatic Attraction

Answer 18

Opposites attract, likes repel

Question 19

Electric current

Answer 19

The rate of movement of electric charge carriers from one part of a conductor to another

Question 20

Electromotive force

Answer 20

a difference in potential that tends to give rise to an electric current

Question 21

Electrical potential difference

Answer 21

The change in potential energy per unit charge between two defined points in a circuit

Question 22

Resistance

Answer 22

The ration of voltage applied to the electric current that flows through it

Question 23

Ohmic resistor

Answer 23

A resistor that behaves according to Ohm’s law

Question 24

Non-ohmic resistor

Answer 24

A resistor that does not behave according to Ohm’s law

Question 25

Kirchhoff’s current law

Answer 25

At any node in an electric circuit, electric charge is conserved such that the sum of the electric currents flowing into a node is equal to the sum of the electric currents flowing out of that node

Question 26

Kirchhoff’s voltage law

Answer 26

The energy inputs in a circuit equal the energy output form loads in the circuit such that the directed sum of the electrical potential difference around any closed network is zero.

Question 27

Power

Answer 27

The rate at which work is done or the rate at which energy is transferred or transformed.

Question 28

Power dissipation

Answer 28

A measure of the rate at which energy is lost from an electrical circuit.