P4-Atomic Structure KW

Question 1

Activity

Answer 1

The rate at which an unstable nucleus decays

Question 2

Alpha Particle

Answer 2

A positively charged particle consisting of two protons and two neutrons

Question 3

Atomic Number

Answer 3

The number of protons found in an atom of a specific element. Each element has a different atomic number

Question 4

Background Radiation

Answer 4

Radiation that is found in small quantities all around us and originates from natural sources such as rocks and cosmic rays, as well as from man-made sources such as nuclear weapons testing and accidents.

Question 5

Becquerel

Answer 5

The unit of radioactive activity

Question 6

Beta Particle

Answer 6

A high speed electron that a nucleus emits when a neutron converts into a proton.

Question 7

Bohr Model

Answer 7

A model of the atom that suggested that electrons orbit the nucleus at set distances.

Question 8

Chain Reaction

Answer 8

The process of neutrons released by a fission reaction, being absorbed by another unstable, large nuclei, and inducing further fission.

Question 9

Count-Rate

Answer 9

The number of decays that a detector measures per second

Question 10

Electrons

Answer 10

A negatively charged constituent of the atom, that are found in different energy levels, around the nucleus.

Question 11

Energy Levels

Answer 11

The stable states in which electrons are found in around a nucleus. Electrons can transition to a higher energy level through the absorption of electromagnetic radiation and can transition to a lower energy level through the emission of electromagnetic radiation.

Question 12

Fission Products

Answer 12

Fission produces two smaller nuclei, two or three neutrons and gamma rays. All these products are released with kinetic energy

Question 13

Gamma Ray

Answer 13

Electromagnetic radiation emitted from a nucleus

Question 14

Geiger-Muller Tube

Answer 14

A detector that measures the count-rate of a radioactive sample.

Question 15

Half-Life

Answer 15

The time it takes for the number of unstable nuclei of an isotope in a sample to halve, or the time it takes for the initial count rate of a sample of the isotope to halve.

Question 16

Ions

Answer 16

Atoms with a resultant charge due to the loss or gain of electrons

Question 17

Irradiation

Answer 17

The process of an object being exposed to nuclear radiation. The object doesn’t become radioactive.

Question 18

Isotopes

Answer 18

Atoms with the same number of protons but different numbers of neutrons. The atomic number is the same, but the mass number is different.

Question 19

Mass Number

Answer 19

The number of protons and neutrons in an atom

Question 20

Negative Ions:

Answer 20

Atoms that gained electrons and so have a resultant negative charge.

Question 21

Neutrons

Answer 21

A neutrally charged constituent of the nucleus.

Question 22

Nuclear Explosions:

Answer 22

Nuclear explosions in nuclear weapons are caused by an uncontrolled chain reaction which results in vast quantities of energy being produced in a very small period of time.

Question 23

Nuclear Fission

Answer 23

The splitting of a large and unstable nucleus into two smaller and more stable nuclei to produce energy.

Question 24

Nuclear Fusion

Answer 24

The joining of two small, light nuclei to form a larger, heavier one and release energy

Question 25

Nucleus

Answer 25

The positively charged centre of an atom, containing protons and neutrons

Question 26

Plum Pudding Model

Answer 26

An old model of the atom that represented the atom as a ball of positive charge, with negative charges distributed throughout it.

Question 27

Positive Ions

Answer 27

Atoms that have lost electrons and so have a resultant positive charge.

Question 28

Protons

Answer 28

A positively charged constituent of the nucleus.

Question 29

Radioactive Contamination

Answer 29

The unwanted presence of radioactive atoms on other materials. It is hazardous due to the decay of the contaminating atoms.

Question 30

Radioactive Decay

Answer 30

The random process involving unstable nuclei emitting radiation to become more stable.

Question 31

Sieverts

Answer 31

The unit used for radiation dosage

Question 32

Spontaneous Fission

Answer 32

Fission that occurs without the absorption of a neutron. Spontaneous fission is rare and in most cases, fission is induced with a neutron.