Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Y10 Physics – Radioactivity etc 1. Explain what happens in radioactive decay. 4. State what each of the three types of radioactivity is made up of. 7. Describe what happens in ionisation and why this is damaging to the human body. 10. Describe the similarities and differences between two isotopes of the same element. 13. Describe what is meant by the ‘specific heat capacity’ of a substance. 2. State the ranges in air for alpha, beta and gamma. 3. State the unit for radioactive decay. 5. State what each type of nuclear radiation can be absorbed by. 6. Explain why a beta source is more suitable than gamma or alpha for monitoring paper thickness. 8. Explain why alpha particles are strongly ionising. 9. State what is meant by the atomic number and atomic mass of an atom 11. Describe the change in mass 12. Describe the change in mass and proton numbers when an and proton numbers when an alpha particle is emitted. alpha particle is emitted. 14. Explain how the density, of particles is different in solids and gases but mass is not. 15. Explain how the energy and movement of particles is different in solids and gases. Y10 Physics – Radioactivity etc – Answers 1. Unstable nucleus of an atom breaks up (decays) and releases particles or radiation. 2. Alpha – a few cm Beta – 0.5 – 1.0 m Gamma – many km 3. Bequerel – Bq - (counts per second) 4. Alpha – 2 protons, 2 neutrons (helium nucleus) Beta – electrons Gamma – electromagnetic radiation 5. Alpha – by thin card Beta by 5mm aluminium Gamma – reduced by thick lead/concrete 6. Paper will absorb some of the beta but not all of it, so the amount of beta getting through changes with the paper thickness 7. Radioactivity collides with an atom and knocks away an electron – damage dna in cells in the body. 8. They have a high mass – more likely to collide with atoms. 9. Atomic number= number of protons (=no. of electrons); atomic mass=no. protons+neutrons 10. Same number of protons; different number of neutrons 11. The atom loses two protons and two neutrons – proton number down by 2; mass number down by 4 12. A neutron decays into a proton and electron; proton number increases by 1; mass number stays the same. 13. The change in thermal energy to raise the temperature of 1kg by 1oC 14. The density in solids is greater than gases – particles are more spread. The total number of particles cannot be created or destroyed. 15. The particles in a gas have more energy; move fast and freely in random directions.