Answer:
The symbol of the ion is A^-
Explanation:
Let A be the symbol of the element.
Proton = 17
Electron = 18
Neutron = 20
Since the element has more electrons than protons, it means it has gain electrons.
From the question given,
The difference between the electron and proton = 18 — 17 = 1
So, the element has gain 1 electron.
Therefore the symbol of the ion is A^-
Answer: 
Explanation:
A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
The double displacement reaction in which one of the product is formed as a solid is called as precipitation reaction.
The balanced molecular equation is:
First, determine the number of moles of gold.
Number of moles = 
Given mass of gold =
Molar mass of gold = 196.97 g/mol
Put the values,
Number of moles of gold = 
=
or
Now, molarity = 
Put the values, volume of ocean =
Molarity = 
= 
Thus, average molar concentration = 
What is a Lewis acid-base reaction?
In the Lewis theory of acid-base reactions, bases donate pairs of electrons and acids accept pairs of electrons.
A Lewis acid is therefore any substance, such as the H+ ion, that can accept a pair of nonbonding electrons. In other words, a Lewis acid is an electron-pair acceptor.
A Lewis base is any substance, such as the OH- ion, that can donate a pair of nonbonding electrons. A Lewis base is therefore an electron-pair donor.
The Lewis theory suggests that acids react with bases to share a pair of electrons, with no change in the oxidation numbers of any atoms.
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