EXCELLENCE TUITION CENTRE
SERVICE WITH EXCELLENCE
RADIOACTIVE TUTORIAL
1. Strontium 90 (9038 sr) undergoes a beta decay to produce element Y. Write
down an equation to show how element y is formed.
2. Uranium 23892 u decays to form nucleus of thorium by emission of an alpha
particle. Thorium has the symbol 23490Th
a. What is the meaning of nucleon number?
b. Write down the decay equation to show how thorium is formed.
c. Thorium decays to an isotope of protactinium, Pa by beta decay. write
down the decay equation to show this process.
3. radioactive isotope has the half-life of 6000years.how many times passes
before the rate of emission from the sample of this isotope falls to the
original value.
4. Phosphorus-32 can decay by emitting beta particles.
a. What is a beta particle?
b. If the proton number of phosphorus is 15,
i. State the new value of proton and mass number of the nuddle
just after it emits the beta particle.
ii. Write down the decay equation for p-32 after emitting two beta
particles.
5. A radioactive material gives a count of 8000 counts per minute. After
20days it gives a count of 500 counts per minute. What is the half-life of this
materials?
6. (a) Name three main types of nuclear radiation and state the nature of
each. [3]
(b) For one of the three main types of nuclear radiation, state any
two properties. [2]
(c) What are radioactive isotopes?
(d) State any one important application of a named radioactive isotopes.
Sodium-24 G14Na)undergoes beta decay with a half-life of 30 hours.
i.
What is meant by the term half-life?
ii.
iii.
Write down the nuclear equation to show the decay of sodium24.
The daughter nuclide formed in the decay is an isotope of
magnesium, Mg)
(e)State the number of protons, neutrons and electrons in one atom of
sodium-24.
(f) If 8g of sodium-24 sample is available at a certain instant, calculate how
long it would take for the sample to decay to one-eighth of the
original mass. [2]