To calculate the total number of atoms in 3CaCl2, we need to consider the number of atoms of each element present in the compound and multiply it by the respective coefficients in the chemical formula.

In 3CaCl2, we have:

- 3 atoms of Calcium (Ca)

- 6 atoms of Chlorine (Cl)

So, the total number of atoms in 3CaCl2 is:

3 atoms Ca + 6 atoms Cl = 9 atoms

Therefore, there are a total of 9 atoms in 3CaCl2.