Atomic Structure

Polonium-210 (²¹⁰₈₄Po) is a radioactive isotope that decays by emitting alpha radiation. Which is the correct decay equation for polonium-210? Tick (✔) one box.

Why is alpha radiation dangerous inside the human body? Tick (✔) one box.

Figure 3 shows how the mass of a sample of polonium-210 changes with time. Determine the change in mass of the sample of polonium-210 between 50 and 150 days.

Using the graph from the previous question, estimate the mass of polonium-210 remaining after 300 days.

Nuclear radiation can cause ionisation. Complete the sentences. Choose answers from the box. <br/> <br/> <table border="1" cellpadding="10" cellspacing="0" style="border-collapse: collapse; font-family: Arial, sans-serif; font-size: 16px; border: 2px solid black;"> <tr> <td style="border: 1px solid black;">a negative</td> <td style="border: 1px solid black;">an electron</td> <td style="border: 1px solid black;">a neutron</td> <td style="border: 1px solid black;">a positive</td> <td style="border: 1px solid black;">a proton</td> <td style="border: 1px solid black;">a zero</td> </tr> </table> <br/><br/> 1. An atom becomes an ion when it loses __________. 2. The resulting ion has __________ charge.

The ancient Greeks thought that atoms were tiny spheres that could not be divided into anything smaller. Since then, different discoveries have led to the model of the atom changing. Some of the discoveries are given in Table 1. **Table 1** <br/><br/> <table border="1" cellpadding="10" cellspacing="0" style="border-collapse: collapse; font-family: Arial, sans-serif; font-size: 15px; border: 2px solid black;"> <tr> <td style="border: 1px solid black; padding: 12px;">The mass of an atom is concentrated in the nucleus.</td> <td style="border: 1px solid black; padding: 12px; text-align: center; font-weight: bold;">A</td> </tr> <tr> <td style="border: 1px solid black; padding: 12px;">Electrons orbit the nucleus at specific distances.</td> <td style="border: 1px solid black; padding: 12px; text-align: center; font-weight: bold;">B</td> </tr> <tr> <td style="border: 1px solid black; padding: 12px;">The nucleus contains neutrons.</td> <td style="border: 1px solid black; padding: 12px; text-align: center; font-weight: bold;">C</td> </tr> <tr> <td style="border: 1px solid black; padding: 12px;">The nucleus contains positively charged protons.</td> <td style="border: 1px solid black; padding: 12px; text-align: center; font-weight: bold;">D</td> </tr> </table> <br/><br/> Which discovery was the earliest? Tick (✔) one box.

Using Table 1 from the previous question, which discovery was the most recent? Tick (✔) one box.

The alpha particle scattering experiment led to the nuclear model of the atom. Figure 5 shows the paths of alpha particles travelling close to a gold nucleus. Complete the sentences. Choose answers from the box. <br/><br/> <table border="1" cellpadding="12" cellspacing="0" style="border-collapse: collapse; font-family: Arial, sans-serif; font-size: 15px; border: 2px solid black;"> <tr> <td style="border: 1px solid black; text-align: center; font-weight: bold;">attracts</td> <td style="border: 1px solid black; text-align: center; font-weight: bold;">decreases</td> <td style="border: 1px solid black; text-align: center; font-weight: bold;">does not change</td> </tr> <tr> <td style="border: 1px solid black; text-align: center; font-weight: bold;">increases</td> <td style="border: 1px solid black; text-align: center; font-weight: bold;">reflects</td> <td style="border: 1px solid black; text-align: center; font-weight: bold;">repels</td> </tr> </table> <br/><br/> 1. Alpha particles and gold nuclei are both positively charged. The gold nucleus __________ the alpha particles. 2. As the alpha particle approaches the gold nucleus, the electric field strength experienced by the alpha particle __________. 3. As an alpha particle approaches the gold nucleus, the force experienced by the alpha particle __________.

The results of the alpha particle scattering experiment were reproducible. What does reproducible mean? Tick (✔) one box.

The process of nuclear fission is used in nuclear power stations. The diagram shows the process of nuclear fission. Complete the sentences. Choose answers from the box. [electrons, gamma rays, neutrons, nuclei, protons] 1. In nuclear power stations, energy is released from uranium _______. 2. The uranium in the diagram splits into two parts and releases three _______. 3. The process of nuclear fission releases electromagnetic radiation in the form of _______.

Radioactive waste produced by nuclear power stations has a long half-life. Suggest **one** precaution taken to reduce the hazard caused by radioactive waste from power stations.