Radioactivity

Question 1

Alpha Radiation

Answer 1

ionizing radiation consisting of alpha particles, emitted by some substances undergoing radioactive decay.

Question 2

Beta Radiation

Answer 2

a high-energy, high-speed electron or positron emitted in the radioactive decay of an atomic nucleus, such as a potassium-40 nucleus, in the process of beta decay

Question 3

Gamma Radiation

Answer 3

Gamma rays with a mass of 0. Have a straight line and no deflection.

Question 4

Radioactive

Answer 4

emitting or relating to the emission of ionizing radiation or particles.

Question 5

Isotope

Answer 5

each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element.

Question 6

Half life

Answer 6

the time taken for the radioactivity of a specified isotope to fall to half its original value.

Question 7

radiometric dating

Answer 7

determining the ages of rocks and fossils based on the rate of decay or half-life of particular isotopes

Question 8

radiocarbon dating

Answer 8

a method of determining the age of a fossil using the remaining amount of unchanged radioactive carbon. All living organisms have the same proportion of radioactive and nonradioactive carbon atoms, but this changes after they die.

Question 9

nuclear reactors

Answer 9

power plant where the radioactive properties of uranium are used to generate electricity

Question 10

Fuel roads

Answer 10

one of the rods that form the fuel source of a nuclear reactor; contains the fissile nuclides needed to produce a nuclear chain reaction

Question 11

Fission

Answer 11

splitting of the nuclei of large atoms into two smaller atoms and several neutrons, releasing radiation and heat energy

Question 12

external radiotherapy

Answer 12

cancer treatment where radiation is directed from an external machine to the site of the cancer

Question 13

internal radiotherapy

Answer 13

cancer treatment is also known as brachytherapy. Radioisotopes are placed inside the body at, or near, the site of cancer.

Question 14

brachytherapy

Answer 14

cancer treatment is also known as internal radiotherapy. Radioisotopes are placed inside the body at, or near, the site of cancer.

Question 15

melt-down

Answer 15

the melting of a nuclear-reactor core as a result of a serious nuclear accident

Question 16

ground zero

Answer 16

centre of a nuclear weapon blast

Question 17

thermal flash

Answer 17

enormous amounts of heat and radiation that spread out from the centre of a nuclear blast

Question 18

electromagnetic pulse

Answer 18

a burst of electromagnetic activity caused by the detonation of nuclear devices

Question 19

Chemical Reactions

Answer 19

a process that involves rearrangement of the molecular or ionic structure of a substance, as distinct from a change in physical form or a nuclear reaction.

Question 20

Exothermic

Answer 20

(of a reaction or process) accompanied by the release of heat.
(of a compound) formed from its constituent elements with a net release of heat.

Question 21

Endothermic

Answer 21

(of a reaction or process) accompanied by or requiring the absorption of heat.
(of a compound) requiring a net input of heat for its formation from its constituent elements.

Question 22

Precipitate

Answer 22

cause (a substance) to be deposited in solid form from a solution.
“cell proteins were then precipitated and washed in 10% trichloroacetic acid”
cause (drops of moisture or particles of dust) to be deposited from the atmosphere or from a vapour or suspension.

Question 23

Reactants

Answer 23

a substance that takes part in and undergoes change during a reaction.

Question 24

Products

Answer 24

a substance that is formed as the result of a chemical reaction.

Question 25

State

Answer 25

one of the ways in which matter can interact with itself to form a homogeneous phase. Examples: solid, liquids, gases, plasma.

Question 26

Aqueous

Answer 26

a solution in which the solvent is water.

Question 27

Coefficients

Answer 27

the number of molecules (or atoms) involved in the reaction.

Question 28

Synthesis Reactions

Answer 28

a type of reaction in which multiple reactants combine to form a single product.

Question 29

Decomposition Reactions

Answer 29

a type of chemical reaction in which a single compound breaks down into two or more elements or new compounds.

Question 30

Combustion Reactions

Answer 30

an exothermic reaction in which something reacts with oxygen.

Question 31

Single Displacement Reactions

Answer 31

a type of chemical reaction where an element reacts with a compound and takes the place of another element in that compound.

Question 32

Double Displacement Reactions

Answer 32

a type of chemical reaction where two compounds react, and the positive ions (cation) and the negative ions (anion) of the two reactants switch places, forming two new compounds or products.

Question 33

Precipitation

Answer 33

the action or process of precipitating a substance from a solution.

Question 34

Acid-base Reactions

Answer 34

a type of chemical process typified by the exchange of one or more hydrogen ions,