A compound is a pure substance composed of two or more different atoms chemically bonded to one another. A compound can be destroyed by chemical means. It might be broken down into simpler compounds, into its elements or a combination of the two.
The molarity of a solution is the number of moles of a substance divided by the volume in liters prepared.
, where n is number of moles and V is the volume in liters.
In order to calculate the mass of solute we need to convert the volume and molarity to moles

Now that we have moles we use the relative formula mass of NaCO₃, We have 1 Na atom, 1 C atom and 3 O atoms, thus


I'm not sure how many sign fig's you are required to have.
However I think the final answer would be 0.05 Moles, because of the .5g, that is considered 1 sign fig.
Answer:
The energy of an electron in many–electron atom is determined by both principal quantum number (n) and azimuthal quantum number (l)