P3 Nuclear atomic structure

Question 1

approx size of the:

• atom
• nucleas

Answer 1

atom: 10@-10
nucleas: 10@-13

Question 2

who invented the plum pudding model

Answer 2

jj thompson

Question 3

describe the alpha particle scattering experiment and how it changed how we see the atom today

Answer 3

the alpha particle scattering experiment is when ernest rutherford fire alpha particles at a thin gold sheet of metal. what happened was:

• majority of atoms went straight through, therefore disproving the plum pudding model
• the fact that some deflected proved that there was a positive centre
• the fact that some bounced straight back proves the nucleas has a great mass

Question 4

what do the following type of radiation omit:

• alpha
• beta
• gamma

Answer 4

alpha- a helium atom
beta- a single electron
gamma- an electromagnetic ray

Question 5

describe three facts about alpha radiation

Answer 5

• dont travel far in the air
• arent very penetrative
• highly ionising

Question 6

describe three facts about beta radiation

Answer 6

• moderate travel in the air
• moderatley penetrative
• moderatley ionising

Question 7

describe three facts about gamma radiation

Answer 7

• travel well in the air
• very penetrative
• weakly ionising

Question 8

describe the medical use of gamma radiation

Answer 8

used as a medical tracer which is swallowed and goes round the body. it can be detected through an external detector and can check to see efficiency of different glands

Question 9

what is a half life

Answer 9

the amount of time it takes for half of the radioactive nuclei to decay in an isotope

Question 10

describe an isotope

Answer 10

something with a different amount of neutrons but the same amount of protons as an element

Question 11

describe background radiation

Answer 11

natural radiation found in everyday life that we are all exposed to

Question 12

give three sources of background radiation

Answer 12

• space
• nuclear waste and spillage
• natural

Question 13

difference between contamination and irradiation

Answer 13

contamination- presence

irradiation-exposure

Question 14

risks of nuclear medicine

Answer 14

• high costs

- no 100% guarnatee

Question 15

describe nuclear fission

Answer 15

an artificial chain reaction where a radioacive isotope recieves a neutron, this then causes the isotope to react and then omit two daughter isotopes alongside two neutrons. the two new isoptopes add up to make the same amount of protons as the original isotope

Question 16

describe nuclear fusion

Answer 16

when two nuclei fuse at high speed to form a larger heavier nucleas and energy

Question 17

describe the plum pudding model

Answer 17

a massive ball with a positive centre and negative electrons