The total number of sodium atoms in 46.0 grams of solution is?

Molar mass Na = 23g/mol
46g = 456/2 = 2mol
1mol = 6.022*10^23 atoms
2mol = 2*6.022*10623
= 1.204*10^24 atoms

First step, is to find the Molar Mass.
If you go to the periodic table, the Molar Mass of the Sodium Na is 23g/mol

Second Step, you convert from grams to moles.
number of Mole = mass of sodium / molar mass = 

Third Step, you find the number of atoms.
As We know, Avogadro said that the number of atoms in 1 mole is about .
You use the Rule of three and you find the number of atoms!
1 mole =  atoms
2 mole = x atomes
x = 2 * (  )
x=  atomes

So, there is  atoms of Sodium Na in 46g of Solution.

Hope this Helps! :D