Explanation:
(1) When a proton is converted into neutron then the positron emission takes place as follows.
A positron is represented by the symbol . Therefore, when a positron emission occurs then the resultant nuclei atomic number decreases by a unit mass.
General equation representing positron emission is as follows.
Hence, Fluorine-18 decays by positron emission as follows.
Therefore, when 18F undergoes positron emission, the product nucleus is, .
(2) Expression for the half-life of a isotope is as follows.
Initial activity, () = 4.00 millicuries
Activity after 95% =
= 0.20 millicuries
t = 7.912 hrs
Thus, we can conclude that it will take 7.91 hrs for 95% of the 18F to decay.
alpha decay is an emission of ₂⁴He
nucleus. If an element undergoes an alpha decay, the mass of the daughter
nucleus formed is reduced by 4 compared to mass of parent atom and atomic
number is reduced by 2 compared to atomic number of parent atom.
Let's assume that the parent atom is X, atomic number is z and mass number is A. Then the formed daughter nucleus, Y should have atomic number as z-2 and mass number as A-4.
The equation is
(z) (A)X → ₂⁴α + (z-2)(A-4)Y
Example:
₉₄²³⁹Pu → ₂⁴α + ₉₂<span>²³⁵U</span>
Answer:
Combination of all the wavelengths of visible light.
Explanation:
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Answer:
The volume of the gas is fixed and will not change.
Explanation:
The volume of the gas will not change because there is no change in temperature. Temperature increases the volume of gases enclosed in a container.