8. Companies delivering radioactive sources have to follow strict safety rules. One

rude is that sources must be labelled. The following information is displayed on a

label on a radioactive source.

Source:

Year of delivery:

Half life:

Activity:

RADIOACTIVE SOURCE

stop clock

(a) (1) State what is meant by an activity of 25 kBq.

(ti) Calculate the activity of the source in the year 2053.

(b) After delivery, the source is placed in a thick walled aluminium storage box.

State which type of radiation from the source, if any, could be detected on

the outside of the storage box. You must justify your answer/

88.88

A technician using an alpha-emitting source investigates its activity using the

apparatus shown below.

beta and gamma emitter

2017

detector

12 years

25 kBa

source

counter

888888

(a) In a time of 2 minutes the counter measures 40 800 counts.

Calculate the count rate measured.

(b) Whilst handling the source, the technician estimates that their hand

receives an absorbed dose of 5-00x 10³ Gy. The mass of the technician's

hand is 400g.

(1) Calculate the total energy absorbed by the technician's hand.

(1) Using information from the data sheet, calculate the equivalent dose

received by the technician's hand.

(6)