Radiation & Risk (AQA GCSE Combined Science: Synergy: Life & Environmental Sciences): Exam Questions

Carbon is an element with several isotopes.

Complete the sentence.

Choose the answer from the box.

Each isotope of carbon has a different number of .

Carbon-14 is radioactive.

Carbon-14 nuclei emit beta particles.

A beta particle is an electron.

Which symbol represents a beta particle?

Tick (✓) one box.

Which two of the following substances would beta particles not be able to penetrate?

Tick (✓) two boxes.

The percentage of carbon-14 in an organism decreases after death.

Figure 3 shows how the percentage of carbon-14 nuclei remaining varies with time.

Determine the percentage of carbon-14 nuclei remaining in an organism after 3000 years.

Use Figure 3.

Percentage remaining = __________ %

The half-life of carbon-14 is the average time taken for the number of carbon-14 nuclei in a sample to halve.

Determine the half-life of carbon-14

Use Figure 3.

Half-life = _________years

Only a very small proportion of the carbon in an organism is carbon-14.

Scientists studying the body from the glacier were not concerned about the risk from beta radiation emitted by the body.

Why was the risk to the scientists low?

Tick (✓) one box.

Carbon-14 emits beta radiation.

Complete the nuclear equation to show the radioactive decay of carbon-14

Use the periodic table.

${ }_6^{14}\text{C}\to { }_{\square }^{\square }\text{e}+{ }_{\square }^{\square }\square$

The amount of carbon-14 in the body had decreased by 47%.

What is the half-life of carbon-14?

Tick (✓) one box.

A student made a statement about a sample of a different radioactive substance.

The student stated:

> ‘If the half-life of the radioactive substance is 30 years, a sample of the substance will not be radioactive after 60 years.’

Explain why the student’s statement is not correct.

Nuclear radiation is dangerous to humans.

Nuclear radiation can change atoms into ions.

Which type of particle is lost when an atom changes into an ion?

A nucleus of uranium$-238\left({}_{92}{}^{238}\mathrm{U}\right)$ emits an alpha particle $\left({}_2{}^4\mathrm{He}\right)$ and decays into thorium $\left({}_{90}{}^{234}\mathrm{Th}\right)$.

Which nuclear equation shows this decay?

How does the penetrating power of alpha particles compare with the penetrating power of beta particles?

Uranium is dug out of the ground in a process called mining.

Uranium mining is hazardous because uranium is radioactive.

The radioactive decay of uranium produces radon gas which is also radioactive.

Table 1 compares the properties of uranium and radon.

Table 1

People who work in uranium mines are more at risk of harm from radon gas than from uranium.

Give two reasons why.

Use Table 1.

Scientists collected data about lung diseases in the population of one country.

The scientists used the data to predict the number of people with lung diseases who worked in uranium mines.

Table 2 shows the predicted data and the actual data for people who worked in uranium mines.

Table 2

Give two conclusions that can be made from the data in Table 2.

Suggest one reason why people who work in uranium mines should be told that uranium is a hazard.

Ionising radiation is dangerous to humans because it causes mutations which can cause cancer.

Which of the following can be mutated by ionising radiation?

Tick (✓) one box.

A nucleus of uranium-238 (U) emits an alpha particle (He) and decays into thorium-234 (Th).

Complete the nuclear equation to show the decay of a uranium-238 nucleus by emitting an alpha particle.

${}_{92}{}^{238}\text{U}\to {}_{-}{}^{234}\text{Th}+{}_2{}^{-}\text{He}$

Rocks from a uranium mine contain uranium and several other radioactive isotopes.

Table 4 shows information about two isotopes in a sample of rock from a uranium mine.

Table 4

The initial number of nuclei of each isotope in the sample was the same.

Explain the difference in the number of nuclei of each isotope in the sample after 5.0 days.

Your answer should include calculations.

Scientists collected data about lung cancer in the population of one country. They used the data to predict the number of cases of lung cancer in people who work in uranium mines.

Table 5 shows the predicted number and the actual number of cases.

Table 5

What was the percentage increase in the actual number of cases compared with the predicted number of cases?

Tick (✓) one box.

Radon is an odourless, colourless gas that builds up in uranium mines.

Radon nuclei emit alpha radiation.

Explain why the actual number of cases of lung cancer in Table 5 is greater than the predicted number.

This question is about radioactive decay.

Figure 7 shows a nuclear equation for the decay of an atom of uranium:

Use information from Figure 7 to complete Table 1.

Table 1

Figure 8 shows how the count rate from a radioactive isotope changes with time.

What is the half-life of the radioactive isotope?

Explain why you chose that value.

Half-life = _______________________________ hours

Explanation: _____________________________

When a radioactive isotope decays it can produce beta particles.

What is a beta particle?

Tick one box.

Beta particles can cause cancer.

Complete the sentences. Use words from the box.

Tumours form when cell division is _____________________________ .

Tumours that do not invade other tissues are called ________________ .

Alpha, beta and gamma are types of nuclear radiation.

A teacher sets up a demonstration of the penetration properties of alpha, beta and gamma radiation.

Figure 3 shows the demonstration.

Complete Figure 3 by writing the name of the radiation in each box.

Give two safety precautions the teacher should take in the demonstration.

Table 2 shows how the count rate of a radioactive source changes with time.

Describe the relationship shown in Table 2.

Use Table 2 to predict the count rate after 200 seconds.

Count rate = _______________counts/second

The half-life of the radioactive source is very short.

Give one reason why the source would be much less hazardous after 800 seconds.

Figure 11 shows how the activity of a radioactive isotope changes over an 8-hour period.

Predict how long it will take for the count rate to fall from 100 to 1.56 Becquerels.

Time = ___________________ hours

Lead-210 is a radioactive isotope that decays to an isotope of mercury by alpha decay.

Complete the nuclear equation to show the alpha decay of lead-210:

${}_{?}{}^{210}\text{Pb}⟶{}_{80}{}^{?}\text{Hg}+{}_{?}{}^{?}?$

Explain how ionising radiation can have hazardous effects on the human body.