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.
The bond order of a diatomic element with six bonding electrons, six non-bonding electrons, and 2 anti-bonding electrons is 2 whose formula is( bonding electrons-anti bonding electrons)/2.
<h3>What is an element?</h3>
An element is defined as a substance which cannot be broken down further into any other substance. Each element is made up of its own type of atom. Due to this reason all elements are different from one another.
Elements can be classified as metals and non-metals. Metals are shiny and conduct electricity and are all solids at room temperature except mercury. Non-metals do not conduct electricity and are mostly gases at room temperature except carbon and sulfur.
The number of protons in the nucleus is the defining property of an element and is related to the atomic number.All atoms with same atomic number are atoms of same element.
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