This question is about the use of radioactive isotopes.
Radiologists working with radioactive sources wear a film badge. Discuss the function of a film badge.
film badge contains photographic film;
which darkens when exposed to radiation;
to monitor the amount of exposure over a period of time;
different filters allow for alpha-radiation, beta-radiation and gamma-radiation to be monitored separately;
One of the side effects of the use of Sr -89 is the reduction of white blood cells in the body, leaving the patient prone to infections. Outline one ethical implication of the choice between using Sr-89 to treat bone cancer and not carrying out treatment.
treatment may lead to other medical complications;
lack of treatment will allow the cancer to spread/increase pain levels;
A group of students is trying to determine the density and the viscosity of a liquid.
To determine the density, they use a balance to read the mass m of a sphere in air and immersed in the liquid.
They use a sphere of volume V=1.827×10−7 m3.
The readings are mair =1.427 g in air and mimmersed =1.208 g in the liquid.
The readings are different due to buoyancy. The buoyancy force Fb is given by
where V is the volume of the sphere and ρ is the density of the liquid.
State the level of precision in the measurement of m.
milligram
OR
0.001 g
Accept half milligram / 0.0005 g
Ignore use of plus/minus
Suggest one reason why doctors use ultrasound rather than X -rays to monitor the development of a fetus.
X-rays are an ionizing radiation and so might cause harm to the developing fetus. OR there are no known harmful effects when using ultrasound
Marking guidance:
Ignore "moving images by ultrasound".