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Answer:</h3>
Sodium
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Explanation:</h3>
- To answer the question we need to know a few things.
What are cations?
- Cations are positively charged ions that are formed when an atom of an element loses an electron(s).
What elements form cations?
- Metallic elements form cations since they react by losing electrons thus forming ions with a positive charge.
- For example, alkali metals such as sodium form cations with a charge of +1.
- In this case, sodium will form a cation with a charge of + 1, Na⁺
What are negatively charged ions?
- Negatively charged ions are known as anions.
- They are formed by non-metallic elements such as sulfur, argon, silicon, etc.
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.
Answer:A
Explanation:
The kinetic molecular theory of matter states that: Matter is made up of particles that are constantly moving. All particles have energy, but the energy varies depending on the temperature the sample of matter is in.This is turn determines shearer the substance exists in the solid, liquid, or gaseous state.
It will not tip over a hot plate