atomic structure : physics only

tracers

• Half-life of 6hrs

• Decays into a safe isotope that can be excreted by the body

• It is injected/swallowed and there is enough time for it flow through the body and be detected before it decays away but is only present for a short enough time to minimise any harm from radiation.

• It is a gamma emitter, so can pass through the body tissue without being absorbed (as it is the most penetrating)

chemotherapy

• Gamma emitters are used to emit gamma rays, which are directed onto certain areas of the body with cancerous cells, which absorb the energy and die, controlling the disease

• It is used to control any other unwanted tissue too

• However, as it is hard to direct accurately, surrounding healthy cells may also be irradiated, and their destruction causes unhealthy side effects

what is nuclear fission

the splitting of a large and unstable nucleus

State one way in which the process of nuclear fusion differs from the process of nuclear fission.

Nuclei are joined and not split

nuclear fission takes place in a..

nuclear reactor

nuclear fusion takes place within a…

star

what is nuclear fusion

when two small nuclei fuse to form a heavier nucleus

describe the process of nuclear fission

• neutron absorbed by nucleus

• forms a larger nucleus

• this larger nucleus is unstable •

• larger nucleus splits into two smaller nuclei

• releasing three neutrons and energy

• after the nucleus splits, it leaves two smaller nuclei roughly equal in size

• And they both have kinetic energy

how is nuclear fission a chain reaction

Nuclear fission is a chain reaction because the neutrons released from the splitting of one nucleus can go on to collide with and split other nearby nuclei, continuing the process and releasing more energy.

how does nuclear fusion occur

Nuclear fusion occurs when two light atomic nuclei collide at high speed and combine to form a heavier nucleus, releasing energy in the process (released as radiation)

what would nuclear fusion be a more efficient way of doing rather than nuclear fission

Fusion would be a much more efficient way of producing energy compared to fission