Quick questions on Half-life and exponential radioactive decay (QCE Physics Unit 1)

6short Q&A pairs drawn directly from our worked dot-point answer. For full context and worked exam questions, read the parent dot-point page.

What is iA1 data test?

Show answer

Often a decay curve to read (activity vs time), with a half-life to extract and a future activity to predict.

What is eA Paper 1?

Show answer

Multiple choice on

(1/2)^n

for integer

n

What is eA Paper 2?

Show answer

A two-part calculation: convert

T_{1/2}

\lambda

, then find activity or number remaining at a non-integer number of half-lives using the exponential formula.

What is q1?

Show answer

State the half-life relationship for the number of nuclei, and find

N/N_0

after three half-lives. [2 marks]

What is q2?

Show answer

A sample of iodine-131 (

T_{1/2} = 8.0 \text{ days}

) has an initial activity of

480 \text{ MBq}

. Calculate the activity after

24 \text{ days}

and the decay constant

\lambda

. [3 marks]

What is q3?

Show answer

A bone-scan dose contains

30 \text{ MBq}

of technetium-99m (

T_{1/2} = 6.0 \text{ h}

). (a) Calculate the activity after

18 \text{ h}

. (b) Determine the time for the activity to fall to

1.0 \text{ MBq}

Have a question we have not covered?

This dot-point answer is short enough that we have not extracted many short questions yet. Read the full dot-point answer or ask Mo, our study assistant, in the chat for follow ups.

All PhysicsQ&A pages