Au is the symbol for gold. It comes from Latin word for gold, which is Aurunum. Its atomic number is 79. 
        
                    
             
        
        
        
Its going to be 2.81 x 1023 atoms 
        
             
        
        
        
<span>Based on the experience of the responder, to correctly calculate measurements in real-world. Firstly is to avoid errors as much as possible. Errors are what makes your measurement invalid and unreliable. There are two types of error which is called the systematic error and the random error. Each error has different sources. Words that were mentioned –invalid and unreliable are very important key aspects to determine that your measure is truly accurate and consistent. Some would recommend using the mean method, doing three trials in measuring and getting their mean, in response to this problem.</span>
        
             
        
        
        
The Molecule of Sodium Formate along with Formal Charges (in blue) and lone pair electrons (in red) is attached below.
Sodium Formate is an ionic compound made up of a positive part (Sodium Ion) and a polyatomic anion (Formate).
Nomenclature:
                        In ionic compounds the positive part is named first. As sodium ion is the positive part hence, it is named first followed by the negative part i.e. formate.
Name of Formate:
                              Formate ion has been derived from formic acid ( the simplest carboxylic acid). When carboxylic acids looses the acidic proton of -COOH, they are converted into Carboxylate ions.
E.g.
                     HCOOH (formic acid)    →     HCOO⁻ (formate)  +  H⁺
                 H₃CCOOH (acetic acid)     →      H₃CCOO⁻ (acetate)  +  H⁺
Formal Charges:
                            Formal charges are calculated using following formula,
           F.C  =  [# of Valence e⁻] - [e⁻ in lone pairs + 1/2 # of bonding electrons]
For Oxygen:
                     F.C  =  [6] - [6 + 2/2]
                     F.C  =  [6] - [6 + 1]
                     F.C  =  6 - 7
                     F.C  =  -1
For Sodium:
                     F.C  =  [1] - [0 + 0/2]
                     F.C  =  [1] - [0]
                     F.C  =  1 - 0
                     F.C  =  +1