Physics - Radioactivity

Question 1

radius of atom?

Answer 1

1x10 -10

Question 2

size of nucleus?

Answer 2

10000 smaller

Question 3

when can electrons absorb electromagnetic radiation?

Answer 3

when they carry correct amount of charge

Question 4

size of electron?

Answer 4

1/2000

Question 5

what is charged atom called?

Answer 5

a ion

Question 6

when can atom become charged

Answer 6

when they transfer electrons to or from

Question 7

3 types of radiation?

Answer 7

Alpha beta and gamma

Question 8

charges of all 3 ?

Answer 8

alpha- +2
beta- -
gamma- none

Question 9

what is ionization?

Answer 9

radiation can knock an electron off an atom and turn it into an ion. This is known as ionisation.

Question 10

what is penetrating?

Answer 10

how easily the radiation can pass through without ionising

Question 11

alpha?

Answer 11

least penetrating
most ionising

Question 12

gamma?

Answer 12

most penetrating
least ionising

Question 13

how far can an alpha particle travel and how can this be stopped ?

Answer 13

alpha particle can travel cm
can be stopped by paper

Question 14

how far can an beta particle travel and how can this be stopped ?

Answer 14

beta particle can travel meters
can be stopped by aluminum

Question 15

how far can an gamma particle travel and how can this be stopped ?

Answer 15

gamma particle can travel several meters
can be stopped by lead

Question 16

what is radioactive decay?

Answer 16

radioactive decay is when and unstable nucleus emits radiation.this is a random process meaning we cannot identify when the nucleus will decay and emit radiation.The radiation can cause other atoms to become ions.

Question 17

what is alpha decay?

Answer 17

alpha decay is when an alpha particle is emitted .The unstable atom will lose 2 protons and neutrons.Atom become different element

Question 18

what is beta decay?

Answer 18

neutron becomes proton .high energy electrons is emitted

Question 19

what is gamma decay?

Answer 19

no change in makeup of unstable atom.gets rid of excess energy .

Question 20

what is half-life?

Answer 20

amount of time it takes for half of the radioactive nuclei to decay.
- the time for the count rarte to go down by a half

Question 21

equation for time passed?

Answer 21

time passed= number of half lives x length of half lives

Question 22

count rate after ‘n’ half lives?

Answer 22

count rate after ‘n’ half lives= initial count rate/ 2n

Question 23

what is contamination?

Answer 23

when radioactive atoms get onto other materials.

Question 24

what is irradiation?

Answer 24

when a object/person is exposed to radiation.

Question 25

uses of radiation?

Answer 25

radiotherapy carbon dating smoke alarms x-rays

Question 26

what is nuclear fission? how can it be controlled?

Answer 26

when a neutron splits a large unstable nucleus into 2 smaller nuclei.this emits energy as well as 3 daughter neutrons which can split other unstable nuclei.this is also known as chain reaction. this can be controlled be the use of control rods.

Question 27

what is fusion?

Answer 27

2 small nuclei releases energy when fused together to create a singular large nucleus.

Question 28

What are the advantages of fusion?

Answer 28

more energy cleaner fuel less harmful emission easily accessible.