the atomic structure
charge of nuclues
positive
charge of electron
negative
realtive mass of proton
1
relative charge of proton
+1
realtive mass of neutron
1
relative charge of neutron
0
mass of electron
roughly 0
realtive charge
-1
mass of the atom is concentrated in the
nucleues
all atoms of the same element have the same number of
protons and nuetrons
what are isotops
element with same protons but different nuetron
when electron move further form the orbit what happens
the atom absorb EM radiation
what happens when the electron move closer to the nuclues
the atom emits EM radiation
what was the sayings of daltons theory
that atom was a big ball of sphere that cannot be divided
who discovered teh electorn
thomson
what was teh name of the new model by thomson
plum pudding
what was the explaination to plum pudding model, and how did he say nuclues was nuetral
it was model conssiting of positive sphere where negative electron where embedded , which made the nuclues nuetral
who conductoded alpha rays expiriments
rutherford
how did we realise the nuclues was charged through alpha rays expiriments
when we did alpha ray expiriment some of the rays go refleceted which means teh nucleues should be oppositly charged
how did we found out most mass was concnetrated in teh cneter of the nuclues from alpha ray expirment
from the expiriment some of the rays were reflected 90 degree which means the mass should be concntrated in the middle
explain the model of rutherford
positive nuclues and negative electorn clouds around them
who produced teh final model
bohr
what was bohrs model explain
proton and nuetron at the center and electron orbiitn it in a fixed position
name of the model of rutherford
nuclur model of atom
what is radioactive decay
a random process where the nuclues give ou radiation inorder to become more stable
what do u mean by activity
is the rate at which source of unstabel nuclie decay
what is activity measured in
bq
what is a count rate
no of decay recoreded by detector per secon [ geiger muller tube]
forms of decay
alpha
beta
gamma
neutron
in alpha decay what happens to mass and charge of the atom
mass number decrease by 4, charge decrease by 2
what happens to mass and charge in beta decay
mass stay the same the charge increaase by 1
what is a half life
time taken for half of the given substance to halve
what is radioactive contamination
unwanted presence of radioacative substance on other material
contamination last for______ period of time
long
what is irradition
exposing an object to radiation, this does not make tha object radioactive
irradation last for_______period of time
short
examples for some weak background radiation
cosmic rays
underground rocks that emit radiation
medical rays
radiation dose is measured in
siverts
uses of radiation
tracers
chemotherapy
what isotops is used for medical tracers
technisium
explain how technitium works as a medical tracers
it haas a half of 6hr
decays into safe isotops that can be escerted from teh body
injected or swallowed it got enough time to betracked down
it is a gamma emitter so it can pass through the tissue without being absorbed
how does chemotherapy works
gamma emiters are used to emmit gamma rays onto certain cancerous cells ad kill the cells,it used to control any other unwanated tissue too.this can also cause unhealhty side effects
what is nucleur fission
splitting up of large and unstble nuclie into two small daugter nuclie
which elements are used for nucluer fission any two
plutonium, urnnium
explains what happens in nucleru fission
an unstabel nuclie absorb a nuclues making it split into two other smaller daughter nuclie.energy is realised in this process
what is nucleur fusion
when two smaller nuclei fuse to from heavy nucleus, releasig a lot of energy