Radioactivity

Question 1

Who discovered radioactivity

Answer 1

Antoine Henri Becquerel

Question 2

unstable of emitting
radiation spontaneously to reach a more
stable state; termed also as radioactive
materials

Answer 2

Radioactive atom

Question 3

conditions why
substance might be
radioactive

Answer 3

Too many protons
Too many neutrons
Too many neutrons
and protons

Question 4

fraction or percentage of original number of atoms decaying per
unit time

Answer 4

Decay

Question 5

The amount of time taken by the radioactive material (RAM) or
radioactive atom to decay to ½ of its original value

Answer 5

Half life

Question 6

Tc99
I131
I123
Ra223
Ra226
Co60
Cs137
Ir192
Sr90
Mo99

Answer 6

6hr
8 days
13hrs
11 days
1620years
5.26 years
30 years
74 days
28years
66 hrs

Question 7

describes the rate of radioactive decay and the
quantity of the material present at any given
time.

Answer 7

Radioactivity law

Question 8

the time required so
that activity of radionuclide is reduced to
50%

Answer 8

Physical half life

Question 9

the time required for the
body to eliminate half of an administered dosage
of any substance by regular process of
deliberation.

Answer 9

Biological half life

Question 10

the time required for a
radioactive elimination in the body to be
diminished by 50% as a result of the
combined action of the Radioactive Decay
and Biological Elimination.

Answer 10

Effective half life

Question 11

excited state last
longer than 10-⁹ second, the term ____ is used

Answer 11

Metastable

Question 12

Nuclear Families

Answer 12

Isotopes
Isobars
Isotones
Isomers

Question 13

the process wherein the unstable atom (parent) spontaneously
emits radiation to reach a more stable state (daughter)

Answer 13

Radioactive decay

Question 14

Any atomic species
characterized by the atomic
mass number (A), protons (Z),
and number of neutron (N

Answer 14

Nuclides

Question 15

the original
nuclide that undergoes
radioactive decay

Answer 15

Parent nuclides

Question 16

more
stable nuclide which results from
radioactive decay.

Answer 16

Daughter nuclides

Question 17

Occurs in heavy nuclides with high atomic number
• It resembles the Helium (He) element

Answer 17

Alpha decay

Question 18

The relative charge of -1 and a mass of 0.
• The β-decay has a moderate energy and it can be stopped by
approximately 0.5mm aluminum or lead.

Answer 18

Beta decay

Question 19

Two modes of beta decay

Answer 19

Negatron emissions
Positron emission

Question 20

s occurs when there are too many neutrons.
• It occurs when a radioactive nuclide with high Neutron and Proton
ratio disintegration

Answer 20

Negatron emissions

Question 21

It occurs when the radioactive nuclide with an excess of Proton
disintegrates
• The particle emitted is positively charged electron which comes from
the nucleus

Answer 21

Positron emission

Question 22

Excited state element
• Radionuclide that yields another nuclide during disintegration
• Long-lived radionuclide

Answer 22

Parent nuclides

Question 23

Ground state element
• Element that results from the radioactive decay of a parent element.
• Short-lived radionuclide

Answer 23

Daughter nuclides

Question 24

originates from the nucleus

Answer 24

Gamma rays & beta particles

Question 25

originates from the electrons

Answer 25

X-rays

Question 26

originate from the e- clouds.

Answer 26

Electrons