Radioactivity

Question 1

Discovery of radioactivity

Answer 1

Becquerel

Question 2

Cathode tubes

Answer 2

Roentgen

Question 3

Term of radioactivity

Answer 3

Currie

Question 4

Atoms mass must be concentrated in an small positive charged

Answer 4

Rutherford

Question 5

Radioactive decay found by

Answer 5

Rutherford

Question 6

What is radioactivity

Answer 6

Spontaneous emission of radiation
Alpha , beta , gamma from nucleus
If a nucleus is unstable it will emit and absorb particles
In order to reach that stability it releases its extra energy by emitting particles or transforming that energy

Question 7

What is Radioactive decay

Answer 7

The process of an unstable nucleus becoming stable by spontaneously emitting particles

Question 8

What is Ionization

Answer 8

The excess amount of energy that unstable nucleuses—removal of electrons from atoms
Uncertain
If there is still excess energy= secondary ionization

Question 9

What is excitation

Answer 9

If the energy transfer is not sufficient to cause ionization.
Transfer of energy to an orbital electron and raising the electron to a higher orbital or energy level.
ONLY DEPENDS ON THE AMOUNT OF ENERGY

Question 10

Half life

Answer 10

Period within which a nucleus has 50% chance of decaying
T1/2

Question 11

Rate of decay

Answer 11

Number of disintegration per unit time
Proportional to the number of unstable nuclei.

Question 12

Average life

Answer 12

Reverse of decay constant
T0= 1/ decay constant

Question 13

Biological half life

Answer 13

Time it takes for a subs to lose half of is radiologic activity

Question 14

Effective half life

Answer 14

rate of accumulation, elimination of a biochemical subs in an organism

Question 15

Belt of stability

Answer 15

Characterization of the stability of nuclides to radioactivity based on their binding energy.
Non-radioactive isotopes exist based on their ratio of neutrons and protons

Question 16

Nuclei which do not fall within the belt of stability called?

Answer 16

Radioactive

Question 17

Heavier elements in belt of stability?
Light elements in belt of stability?

Answer 17

Light= non-radioactive nuclei contain approximately equal number of protons and neutrons
Heavier = non-radioactive nuclei contain more neutrons than protons.

Question 18

Origins of X-rays and Gamma rays

Answer 18

X-rays: from electron transitions, orbitals
Gamma: from nucleus

Question 19

Radioactivity unaffected by

Answer 19

Temperature
Pressure
Physical state

Question 20

Decay modes?

Answer 20

Alpha decay
Beta decay
Gamma decay
Spontaneous fission
Delayers neutron and proton emission
Two proton decay
Composite particle emission
Double beta decay

Question 21

The transition of a neutron into a proton?

Answer 21

If the unstable nucleus is above the belt
Release of a NEGATRON from nucleus

Question 22

The transformation of a proton into a neutron?

Answer 22

Unstable nucleus below the belt of stability
Release of a POSITRON from the nucleus= p/n increases
Capturing an extra nuclear electron usually from K shell= K-CAPTURE

Question 23

What kind of a decaying happens when unstable nucleus is beyond the belt of stability

Answer 23

Emission of an alpha particle from the nucleus
Z bigger than 83
Too many p so unstable

Question 24

In the decays conversion of ?

Answer 24

Energy
Momentum
Electric charge
Number of nucleons