True The positive electric charge of a proton is equal in magnitude to the negative charge of an electron; therefore, the net electric charge of an ion is equal to its number of protons minus its number of electrons. Ions are highly reactive species.
<span>This means that has great capacity to react with other chemical elements in nature, reacting mainly with sodium, therefore, can only be findings in chemical compounds in most cases.
hope this helps!.</span>
As you have not provided the options, still we can figure out the answer by understanding the key difference between saturated and unsaturated hydrocarbons.
SATURATED HYDROCARBONS are those hydrocarbons which only consist of a carbon carbon single bonds. All the bonds are sigma there are no pi bonds at all. Examples are shown below.
While, UNSATURATED HYDROCARBONS are those hydrocarbons which may contain either a double bond or triple bonds or both of them between the carbon atoms as shown below.
Answer: The new pressure is 3 psi.
Explanation:
Given:
= 12 psi, 
= ?, 
Formula used is as follows.

Thus, we can conclude that the new pressure is 3 psi.