Nuclear Reactions Flashcards
atomic number
- number of protons in the nucleus
- used to identify the element
mass number
- number of protons plus neutrons
- used to identify the isotope of the element
isotope
same number of protons but different number of neutrons/ same atomic number but different mass number
isotopes of an element have similar chemical properties but undergo different nuclear reactions.
what is emitted in alpha decay?
two protons and two neutrons (helium nucleus)
what happens to atomic and mass number after alpha decay?
- mass number decreases by 4
- atomic number decreases by 2
when does beta decay occur?
when a neutron decays into a proton and an electron which is emitted from the nucelus
what happens to atomic and mass number after beta decay?
- mass number unchanged
- atomic number increases by 1
what is emitted in gamma decay?
isotopes emit a high-energy photon of electromagnetic radiation
what happens to atomic and mass number after gamma decay?
gamma emission does not affect the atomic number or mass number.
symbol for proton (read AZX)
1 1 P
symbol for neutron (read AZX)
1 0 n
symbol for electron (read AZX)
0 -1 e
symbol for alpha (read AZX)
4 2 He
symbol for beta (read AZX)
0 -1 e
what are the two types of nuclear fission?
spontaneous and induced
spontaneous fission
natural process in which a larger nucleus splits into two smaller nuclei
also releases neutrons
induced fission
nucleus bombarded by a neutron and then becomes unstable
separates into two nuclei and emits neutrons which can then bombard other nuclei (chain reaction)
nuclear fusion
process in which two nuclei combine to form a nucleus of larger mass number
the sun uses…
fusion to generate energy
what isotopes of hydrogen combine to form helium in nuclear fusion?
deuterium and tritium
equivalence of mass and energy
in all nuclear reactions the mass before is greater than the mass after
this is because some of the original mass has been converted into energy
E=mc^2
fusion reactors
require charged particles at a very high temperature which have to be contained by magnetic fields
approximate temperature of fusion reactors?
10 million kelvin
problem of high temperature in fusion reactors?
- produces a plasma that needs to be contained inside the reactor vessel.
- this is done using a very powerful magnetic field produced by electromagnets
- great deal of power required to maintain the electromagnets.
- hot enough to melt/evaporate walls of reactor.
what is a further issue with fusion reactors?
once a reactor is up and running, there are further issues with extracting energy from the plasma as the reactor continues to run.
