Physics Topic 6 Homework 1: Inside Atoms, Background Radiation

Inside Atoms

Background Radiation

1. Where are the positive charges in an atom? / 6. What happens to electrons when the atom loses energy? / 11. What is the name of the model that helps to explain the properties of materials? / 16. Rutherford investigated the structure of the atom. What did he do?
2. What particles in an atom have negative charges? / 7. What is ionisation? / 12. Which of the following is approximately the diameter of an atom – a hundredth of a millimetre, a thousandth of a millimetre or a millionth of a millimetre? / 17. What happened to most of the alpha particles in Rutherford’s experiment?
3. How are electrons arranged in an atom? / 8. What charge does an ion have when it has lost an electron? / 13. What charge do electrons have? / 18. Why did Rutherford conclude that most of the mass of the atom was in the centre?
4. What happens to one or more electrons when an atom gains energy? / 9. Name one source of background radiation in everyday life. / 14. How much mass do electrons have? / 19. What is the relative mass of a proton?
5. Name two ways in which an atom can gain energy. / 10. Name one thing that can detect radiation. / 15. In Thompson’s model, the atom was positively charged with tiny negative charges in it. What was this model called? / 20. What are isotopes?
1. Where are the positive charges in an atom? (nucleus) / 6. What happens to electrons when the atom loses energy? (They fall to a lower orbit/shell/energy level.) / 11. What is the name of the model that helps to explain the properties of materials? (kinetic theory/model or particle theory/model) / 16. Rutherford investigated the structure of the atom. What did he do? (He fired alpha particles at gold foil.)
2. What particles in an atom have negative charges? (electrons) / 7. What is ionisation? (when an atom absorbs enough energy to let an electron escape completely) / 12. Which of the following is approximately the diameter of an atom – a hundredth of a millimetre, a thousandth of a millimetre or a millionth of a millimetre? (millionth of a millimetre) / 17. What happened to most of the alpha particles in Rutherford’s experiment? (went straight through)
3. How are electrons arranged in an atom? (orbits/electron shells around the nucleus) / 8. What charge does an ion have when it has lost an electron? (positive) / 13. What charge do electrons have? (negative, or –1) / 18. Why did Rutherford conclude that most of the mass of the atom was in the centre? (A few particles bounced back.)
4. What happens to one or more electrons when an atom gains energy? (jump to higher orbits/shells/energy levels) / 9. Name one source of background radiation in everyday life. (any sensible source, such as space, food, rocks etc.) / 14. How much mass do electrons have? (negligible/hardly any) / 19. What is the relative mass of a proton? (1)
5. Name two ways in which an atom can gain energy. (any two from: by heating, by electricity, by electromagnetic radiation) / 10. Name one thing that can detect radiation. (Geiger–Müller tube/photographic film) / 15. In Thompson’s model, the atom was positively charged with tiny negative charges in it. What was this model called? (plum pudding model) / 20. What are isotopes? (atoms of the same element with different masses)

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