Download types of radiation : quiz 3

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.