1. Break down the formula:
* Na₂S₂O₃: This represents sodium thiosulfate.
* 5H₂O: This represents five water molecules.
2. Count the atoms in each part:
* Na₂S₂O₃:
* 2 sodium atoms (Na)
* 2 sulfur atoms (S)
* 3 oxygen atoms (O)
* 5H₂O:
* 10 hydrogen atoms (H) (5 molecules x 2 hydrogen atoms per molecule)
* 5 oxygen atoms (O) (5 molecules x 1 oxygen atom per molecule)
3. Add up the atoms from both parts:
* Total atoms: 2 Na + 2 S + 3 O + 10 H + 5 O = 22 atoms
Therefore, there are 22 atoms represented in the formula Na₂S₂O₃·5H₂O.
