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
RADIOACTIVITY EQUATIONS : QUIZ 3 You will need paper to write down your answers to the questions. You can then check your answers against those provided at the end. You should not need more than 10 minutes to answer all the questions in this quiz. QUESTION 1a: What is a beta particle? [1] QUESTION 1b: Caesium (Cs) decays to barium (Ba) by the emission of a beta particle. If the caesium has a mass number of 137 and a proton number of 55, write an equation to represent the decay.[4] Click again for a hint! Hint: use 0 -1 e to represent the beta particle. and remember, mass must be conserved QUESTION 2 a) What is an alpha particle composed of? [1] b) What is the mass number and the proton number of an alpha particle? [2] c) Element X has 98 protons and 94 neutrons in its nucleus and decays to element Y by the emission of an alpha particle. Write an equation to illustrate this. [4] Click again for a hint. X Y + a … Now fill in the mass and proton numbers QUESTION 3 : last question The equations below represent the radioactive decay of various radionuclides. The particle of radiation is represented by an ‘x’. Look carefully at the equations and determine what type of particle ‘x’ represents in each case. a) 226Ra 88 222Rn 86 + x [1] b) 137Cs 137Ba 56 + x [1] 55 c) 40Rs 27 36Po 25 + x [1] ANSWERS : Credit yourself with marks as suggested. Words in brackets help to make your ideas clearer (but are not necessary for the mark). Words that have been underlined must be used in your answer to get the mark. Question 1 a) A beta particle is a (fast-moving) electron. [1] b) 137Cs 55 1 mark for having 137 and 55 in the right places 137Ba 56 1 1 + 0e -1 1 for remembering the symbol for an electron QUESTION 2 a) Two protons and two neutrons [1] b) an alpha particle has a mass number of 4 [1] and a proton number of 2 [1] [1] c) [1] [1] [1] 192X 98 188Y 96 + 4a 2 Marks will be credited for writing the proton number (98) in the right place, 1 mark for calculating and writing in the correct mass number (98+ 94 =192). One mark for the correct mass and proton numbers of element Y QUESTION 3 : last question Whenever radioactive decay occurs, the total mass must always be conserved. If you add up the numbers at the top (representing the mass number) you should get the same number on both sides of the equation. The same applies for the proton numbers (the numbers to the bottom left). 222Rn + x a) 226Ra ‘x’ is an alpha particle..[1] 88 b) 137Cs 55 c) 40Rs 27 86 137Ba 56 + x ‘x’ is a beta particle..[1] 36Po + x ‘x’ is an alpha particle..[1] 25 Make sure that you keep a record of your answers and your total score. It is especially important that you take note of which questions you got wrong.