Answer:
Balance the nuclear equation
43
19K −→ 43
20 Ca + ?
1. ? = 1
0n
2. ? = 1
1p
3. ? = 43
18Ar
4. ? = 0
−1
β
5. None of these
6. ? = 43
−1
e
7. ? = 0
1
e
8. ? = 1
0n
9. ? = 2
3He
10. ? = 4
−1
p + e- + α
11. ? = 40
24Mg + β+ → 20 22Ne + γ
12. ? = 0
13C(β-)13N(e-)13C* → 13N(β-)13C(γ)13O + γ
The previous article was about the first step of fission process. The second step of fission is called secondary nuclear reaction, which includes the alpha decay and beta-minus (negative electron), beta-plus (positive electron), and gamma (high energy X-ray) emissions. Secondary nuclear reactions produce more neutrons than those produced by primary nuclear reaction.
The combining of two nuclei with less mass number than the original is called alpha decay, whereas, taking off a beta particle from nucleus is called beta-minus (negative electron), if the nucleus takes off a beta particle and proton, it is called beta-plus (positive electron), and a gamma ray with extremely high energy is called gamma emission.
The secondary nuclear reactions produce more neutrons than those produced by primary nuclear reaction. There are 5 common secondary nuclear reactions that can be seen in the fission process, as follows:
Alpha decay: α
Beta-minus (negative electron): β−
Beta-plus (positive electron): β+
Gamma emission: γ
Positron emission: β+
Explanation:
Alpha decay is a process in which a radioactive isotope emits an alpha particle and transforms into the element with 2 less protons. For example:
"43 19K → 20 22Ne + α"
In the previous equation, K-19 transforms into Ne-22 through alpha decay. The mass number decreases by 4 and the atomic number increases by 2. For instance 17O-16 becomes 18F-19 when it decays to fluorine. In this process, the mass number decreases by 4 and the atomic number increases by 2.
Beta-minus (negative electron) is a process of emitting an electron with negative charge from the nucleus. The electron that moves out of the nucleus has less energy than beta particle emitted during beta decay, which means it can be stopped easily with just a piece of paper.
Beta-minus (negative electron): β−
For example: "14 7N → 14 7C* + β−"
In the previous equation, N-14 transforms into C-14 through beta minus. The mass number remains unchanged and the atomic number decreases by 1. For instance 8O-15 becomes 8F-14 when it decays into fluorine. As the beta particle emitted in this process is negative, so the mass number remains unchanged and the atomic number decreases by 1.
Beta-plus (positive electron) is a process of emitting an electron with positive charge from the nucleus. The electron that moves out of the nucleus has more energy than beta particle emitted during beta decay, so it can be stopped only by special means like aluminum foils or other very dense materials.
Beta-plus (positive electron): β+
For example: "8 7Be → 8 4He + β+"
In the previous equation, Be-8 transforms into He-4 through beta plus. The mass number remains unchanged and the atomic number decreases by 2. For instance 14N-15 becomes 14O-8 when it decays into oxygen gas. As the beta particle emitted in this process is positive, so the mass number remains unchanged and the atomic number decrease by 2.
Gamma emission is a process of emitting electromagnetic waves from nuclei with no change to nuclear structure. Gamma radiation has less frequency than X-rays but higher energy, so gamma rays are very powerful radiation means that can pass through human body easily, whereas X-ray has less power so cannot pass through human body easily. Gamma rays are also used for imaging purposes because they are high penetrating power source which allows scientists to see inside opaque objects like humans or rocks without harming people or things.
Gamma emission: γ
For example: 2 1H → 1 0n + γ"
In the previous equation, H-2 transforms into neutron through gamma emission. The mass number remains unchanged and the atomic number is decreased by 1. For instance 13N-14 becomes 14O-13 when it decays into oxygen gas with radiation of gamma ray. As this process does not change the mass number so the atomic number decreases by 1.
Positron emission is a process in which an electron with positive charge moves out of nucleus to form an atom of anti-matter (the anti-particle). If matter and anti-matter collide each other they destroy themselves, but positrons are used in medicine for imaging because they emit radiation.
Positron emission: β+
For example: 1 1H → 1 0n + γ + β+"
In the previous equation, H-1 transforms into neutron through gamma emission and beta plus emission. The mass number remains unchanged and the atomic number is decreased by 2. For instance 13N-14 becomes 14O-13 when it decays into oxygen gas with radiation of positrons and gamma rays. As this process decreases the atomic number by two, so the mass number remains unchanged during decay process.
