atomic structure

Question 1

what are in atoms

Answer 1

postive charged protons, neutral neutrons, negative charged electrons

Question 2

what is energy lever

Answer 2

the energy level of distance of electrons from atom

Question 3

further away it is from energy level…

Answer 3

higher energyy

Question 4

when can energy level change

Answer 4

absorb electromagentic radition from low energy level to high
emission of electrogmgetnci raditon from high level go back orginal.

Question 5

what is a isotope

Answer 5

atom same number of protons but different number of neutrons

Question 6

what is atomic number

Answer 6

number of protons equal to the number of electrons

Question 7

what is the mass number

Answer 7

Number of protons plus neutrons

Question 8

what happens when atom loose a isotope

Answer 8

atom turn postive ion

Question 9

what was Dalton theory

Answer 9

atoms thought tiny and soild sphere that can’t be subdivided or broken

Question 10

devlopment of atom -

Answer 10

1. thought tiny sphere can’t be subdivided or broken - Dalton
2. Plum pudding model, atom is ball of psotive charge with negative electron embedded- Thompson
3. Alpha scattering experiment, nuclear mdoel replace plum pudding conclsuion of mass of atom concentraed at centre and was charged with +, - – Rutherford
4. Bohr experiment and observaton, adpat nuclear model by suggest that electron orbit cuclear specific distance
5. Rutherford more experiment - protons name was given
6. Chadwick, show existenc of neutron in nuclear.

Question 11

what is radioactive decayy

Answer 11

isoptope unstable nucleaus in becoming stable nucleus give radition, in random process

Question 12

what is activity + unit

Answer 12

rate at which a source of unstable nuclei decays. becquerel,Bq

Question 13

what is a count-rate

Answer 13

number of decays recorded each second by detector.

Question 14

what detector use for count rate and activty of source

Answer 14

gieger-muller tube

Question 15

what is alpha element like - what happes

Answer 15

4 HE 2, subtratcing 4 and 2

Question 16

what is beta elemnt like - what happens

Answer 16

0 E -1, adding 1

Question 17

nuclear radiation types

Answer 17

alpha, btea, gamma, neutron

Question 18

what is alpha + sign

Answer 18

2 protons and 2 neutrons, same as helium nucleus

Question 19

what ionising is alpha and passess through

Answer 19

strong, pass through single sheet paper

Question 20

how long alpha in air and where from nucleus

Answer 20

5cm, ejected from nucleus

Question 21

what hazard is alpha

Answer 21

highly likely absorved causes damage if pass through live cells

Question 22

what is beta raditiaion and sign

Answer 22

high speed electron ejected from nucleus as a neutron turns into proton.

Question 23

what ionsing and passess throgh beta

Answer 23

moderately, pass thorugh paper but stops at aluminiium

Question 24

how long beta in air and from where in nculeus

Answer 24

15cm, ejected from nucleus

Question 25

what hazard is beta

Answer 25

damage if absorbed in cells and can penetrate body to inner organs

Question 26

what is gamma ray and sign

Answer 26

electromagnetic radiation from nucleus

Question 27

what ionsing and passes through gamma

Answer 27

least ionsing, and pass through paper, aluminium and lead

Question 28

how long in air is gamma and from where in nuclues

Answer 28

several metres in air before stop, and emitted from nucleus

Question 29

the hazrad of gamma ray

Answer 29

pass through living cells without absorbed and cause ionisation

Question 30

what are advantagge of long isotope half-life

Answer 30

-stable -emit radioation slowly ( less hazardous exposure) -remain radioactive.

Question 31

what are advatage of short isoptoe half-life

Answer 31

-unstable -emit radiation faster (exposure to hazardous) -not remain radioactive for long

Question 32

where does bakcground radition come from

Answer 32

natural sources and man made

Question 33

natural sources types in background radiation

Answer 33

- radioactive rock , ground find with granite -cosmic ray from space, very high enrgy particles travel through space and crash into earth atmosphere

Question 34

man made types of background radiatiom

Answer 34

-Fallout from nuclear weapon testing, release radioactive isotope into environment for decades. -Nuclear accident, radioactive isotope realse by accident at nuclear power station

Question 35

what is irradiation

Answer 35

exposure an object to nuclear radiation

Question 36

danger of irradiation to human

Answer 36

damage cells, DNA, cause cancer

Question 37

example of irradiation

Answer 37

sterelization to kill bacteria, medical equipement sterlised by heating.

Question 38

irridation method to object for sterlise syringe

Answer 38

1. place inside sealed plastic wrapper to stop bacteria enter after sterliling 2. place object near radioactive isotope that emit gamma radiaition to irrdate objects

Question 39

what is radioactive contamination

Answer 39

unwanted presnese of materials containing radioactive atoms on other material

Question 40

what is contamination

Answer 40

occur when object is exposured to source of radiation outside the object

Question 41

hazard of radioative ccontamination

Answer 41

- decay of contaminating atoms -burns -cancer risk - contaminate soil

Question 42

what is nuclear radiation used for in medicine

Answer 42

-exploartion of internal organs -control or strcution of unwnated tissue

Question 43

what is tracer

Answer 43

radioactive isotope into system

Question 44

example of nuclear radition in medicine

Answer 44

- medical tracer exploration of internal organ, radioactive isotpe injected/ingested into body so movement can track and dectected outside. -monitor kidney function, isotope will pass through kidney used -look for damage/blockage intensines, detect tumour

Question 45

why must tracer have short life

Answer 45

so not present in body for long period

Question 46

what is nuclear fission

Answer 46

splitting of large and unstable nuclues

Question 47

what happens during nuclear fission + show

Answer 47

split into 2 smaller nuclei and emit2/3 neutrons and gamma ray, energy released

Question 48

what must be absorbed for nuclear fission, and involve

Answer 48

a neutron and involve chain reaction

Question 49

what is chain reaction

Answer 49

controlled in nuclear reactor to control the energy released

Question 50

what is nuclear fusion

Answer 50

joining 2 light nuclei to from a heavier nucleus

Question 51

what happens to mass in nuclear fusion

Answer 51

some mass may be converted into the energy of radiation

Question 52

Proton , neutron , electron relative charge

Answer 52

+1,0,-1

Question 53

Proton , neutron , electron relative mass

Answer 53

1,1,1/2000

Question 54

What happens in chain reaction of nuclear fission

Answer 54

After spliting nucleus into 2 smaller nuclei and emitting 2/3neutron, gamma Ray. Neutron emitted can then be absorbed by more uranium nuclei and trigger fission again.

Question 55

half-life of radioactive isotope means

Answer 55

time taken for atoms of the isotopes in a sample to halve

Question 56

explosion in a nuclear weapon is cause by.....

Answer 56

uncontrolled fission chain reaction

Question 57

radioactive means

Answer 57

substance that give out alpha radiation

Question 58

what is alpha best source use for

Answer 58

smoke detector cos do not travel far in air

Question 59

what is beta and gamma best source use for

Answer 59

btea - thickness of material cos have enough energy to pentrate materials. gamma - tracer / sterilise food cos longer halflife and least iosning

Question 60

what happens for short half life

Answer 60

when decay rapidly causng great hazard - high radiation level

Question 61

what happens for long half life

Answer 61

when decay slowly causing less hazard - low radiation level