A sample contains atoms of a particular isotope of lead, YXPb_Y^X\text{Pb}YXPb.
A nucleus of this lead isotope contains 82 protons and 128 neutrons.
State the values of XXX and YYY in the symbol YXPb_Y^X\text{Pb}YXPb.
X=X = X= _______
Y=Y = Y= _______
This isotope is radioactive and it decays by the emission of a β\betaβ-particle, −10β_{-1}^{0}\beta−10β, to an isotope of bismuth, Bi\text{Bi}Bi.
Complete the equation for the decay of a lead nucleus:
……Pb→ −10β +……Bi \dots\dots \text{Pb} \rightarrow \, _{-1}^{0}\beta \, + \dots\dots \text{Bi} ……Pb→−10β+……BiA radiation detector measures a background count rate in a laboratory of 30 counts/minute.
Suggest two naturally occurring sources of background radiation.
The lead sample is placed in the laboratory close to the radiation detector, and the total measured count rate increases to 270 counts/minute.
This isotope has a half-life of 45 minutes.
Predict a value for the count rate measured 135 minutes later.
Suggest one reason why the count rate measured 135 minutes later may differ slightly from the value predicted in (b)(ii).
484 exam-style questions on CIE IGCSE Physics 5.2 Radioactivity, covering 5.2.1 Background radiation and measuring count rate, 5.2.2a Alpha, beta and gamma emission, 5.2.2b Deflection and ionising effects of nuclear radiation, 5.2.3a Radioactive decay, 5.2.3b Effects of decay on the nucleus and decay equations, 5.2.4a Half-life, 5.2.4b Choosing isotopes for applications, and 5.2.5 Effects of ionising radiation and safety precautions. Each one has a worked solution and a mark scheme showing where the marks go.