says that H10Na2O8S2 is wrong and also Na2S2O3 5H20 is wring i dont understand if im puting the wrong formula

Sulfur is present in a wide variety of compounds, including acid rain, fool's gold and other ores, important preservatives, and laboratory reagents. Sodium thiosulfate pentahydrate is used in iodineclock reactions and iodometric titration experiments. Write the chemical formula for sodium thiosulfate pentahydrate