Download Particular particle knowledge

Particular particle knowledge – radioactivity
1.
Atoms are made up of three principle particles - protons, neutrons and electrons.
Complete the table below which compares their properties.
Particle
Relative mass
Charge
protons
neutrons
electrons
2.
This is a representation of an atom. Label A, B, and C.
A
.........................................................
B
.........................................................
C
.........................................................
3.
Why do atoms have no net charge? ..........................................................
4.
If an atom loses or gains an electron, it becomes a charged particle or ...............
......................................................................................................
5.
What does the top number represent, atomic mass or atomic number?
......................................................................................................
What does the lower number represent, atomic mass or atomic number?
......................................................................................................
12
6
6.
C
In any atom, the atomic number is ...........................................................
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Particular particle knowledge – radioactivity
7.
In any atom, the atomic mass is ..............................................................
8.
Here is a mystery element. What can you say about it?
........................................................................................
148
74
A
........................................................................................
........................................................................................
9.
Using the same method as in Q8 for showing the information, how would a helium
atom be represented?
......................................................................................................
10. Which sort of radioactive particle is a charged helium nucleus?
......................................................................................................
11. Do all atoms of the same element have the same number of protons?
......................................................................................................
12. Some atoms of the same elements have a different number of .........................
13. These atoms are called .........................................................................
14. The nuclei of six unidentified elements are shown below. Circle the ones which are
isotopes of each other.
92
48
125
47
92
38
92
39
121
45
132
47
15. What helped you decide your answer to question 14? ....................................
......................................................................................................
......................................................................................................
16. What is a radioactive isotope? ...............................................................
17. What happens when a radioactive isotope breaks down and what do we call this
‘breakdown’?
......................................................................................................
......................................................................................................
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Particular particle knowledge – radioactivity
18. Following radioactive decay, what three types of radiation could be emitted?
1. ................................ 2. ................................ 3. ...........................
19. Which one has a negative charge? ............................................................
20. Describe where and how this type of particle is formed. .................................
......................................................................................................
21. Fill in the empty boxes.

Alpha particle =

Beta particle =
22. Look at the isotopes below. Choose one to complete the equations.
a) V  ................ +
92
48
125
47

b) W  ................ +
92
38
92
39
121
45

132
47
Neutrons are used in nuclear fission (fission means splitting) to split some very
large unstable nuclei. What is released when this happens and what is formed?
......................................................................................................
......................................................................................................
......................................................................................................
If the conditions are correct, the neutrons can then continue the process. What
name do we give to this type of reaction?
......................................................................................................
......................................................................................................
......................................................................................................
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Particular particle knowledge – radioactivity
Answers
1.
Particle
protons
neutrons
electrons
Relative mass
1
1
0
Charge
+1
no charge
-1
2. a) – electron, b) - proton, c) – neutron.
3. They have the same number of positively charged protons as negatively charged
electrons.
4. Ion.
5. Atomic mass, atomic number.
6. The number of protons.
7. The total the number of protons plus the number of neutrons.
8. Atomic number of 74 (74 protons), atomic mass of 148,74 neutrons, 74 electrons.
9.
4
He
2
10. An alpha particle.
11. Yes.
12. Neutrons.
13. Isotopes.
14. V and Z.
15. By looking for the same number of protons - in this case V and Z both have 47.
16. It is an unstable isotope.
17. Emits nuclear radiation. Radioactive decay.
18. alpha (), beta particles (), gamma radiation ( )
19. Beta particle.
20. Formed in nucleus when a neutron changes to a proton (n  p+ + e-).
21.
4
2
22.
23.

125
47
v
92
38
W
0
-1
121
45
92
39

Y+
x+
4
2

0
-1

24. Nuclear energy is released. At least two new smaller nuclei and two or three
neutrons are formed.
25. A chain reaction.
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