Learner name: ______________________________

Examination number: ________________________

Investigating nuclide notation and the safe storage and handling of sealed radioisotope sources

Submission details

• Time available: 2hours
• Working arrangement: Individual

Investigative practical Details

Your school keeps a small science display of sealed radioactive sources whose labels must show each source's nuclide notation and its safe storage and handling instructions. No real radioactive material is used by learners, so this investigation is a simulation using printed source cards. Use the local context described in this assessment. Investigate how the data printed on each source card can be used to construct its nuclide notation, and decide how such a source should be stored and handled safely in a school laboratory. The card data are given in Table 1. You plan your own method; you are assessed on your plan, your practical work with the cards, your record, your analysis and your evaluation of the simulation.

Table 1: Data printed on the simulated source cards

Instructions

• Work individually and use only the supplied source cards and printed reference information.
• The cards are paper models only: do not cut, tear, burn, taste or damage them, and do not bring any real radioactive material or unapproved item into the laboratory.
• Submit your investigation plan and safety checklist for approval before you begin practical work.
• Record in ink; cancel an error with a single line and write the correction beside it.
• Wash your hands after handling the cards.

Required work

• Your approved written plan: aim, variables and method.
• Your safety checklist.
• Your completed record table of nuclide notation and particle counts for every card.
• Your storage and handling plan for the display.
• Your written analysis answers, conclusion and evaluation.

Resources

• Paper and pens
• Ruler
• Recording sheet
• Printed reference information for offline use, including the Table 1 source-card data
• Simulated source cards prepared from Table 1

Task safety

• No real radioactive material is used; the cards are paper models only. Do not bring radioisotopes, luminous watch dials, luminous paint, smoke detectors, mineral specimens or any other unapproved item into the laboratory.
• Do not cut, burn, taste or open the cards.
• Keep the bench clear and lay cards flat so they cannot fall or be mixed up.
• Wash hands after handling the cards.
• Practical work begins only after the teacher has approved the plan and safety checklist and is supervising the session.

Investigation stage 1

Plan your investigation. State your aim, identify your independent, dependent and controlled variables, and describe the method you will use, including how you will record each card and how you will check your work. Add a safety checklist. Submit for approval before starting practical work.

Investigation stage 2

Carry out your approved method. For each card in Table 1, construct the nuclide notation and record the number of protons, neutrons and electrons in the atom. Complete the record table below.

Table 2: Record of nuclide notation and particle composition

Investigation stage 3

Use your record to explain how A and Z relate to the particles in an atom, and explain why two cards with different mass numbers but the same atomic number are called isotopes. Then complete the decision table, giving one storage rule, one handling rule and a reason for each card.

Table 3: Storage and handling decisions

Investigation stage 4

Evaluate your investigation: state one limitation of using paper source cards instead of real sources, one error that could affect your record and one improvement. Then write a conclusion that answers your aim.

Evidence / logbook

• Record the aim and variables you finally used before you begin work.
• Note the order in which you examined the cards and any card you re-checked.
• Note one thing your plan did not cover and what you decided to do about it.

Keep dated observations and individual contribution records in your logbook.