To calculate the calcium particles that are needed we must take into account Avogadro's number, this number tells us that in one mole of any substance there are 6.022x10^23 particles.
So if we have 3 moles of Calcium (Ca), we must multiply this value by 3 to obtain the number of particles of Ca, that is, we apply the following operation.
![\begin{gathered} \text{Particles of Calcium}=GivenmolCa*(6.022*10^(23)particlesCa)/(1molCa) \\ \text{Particles of Calcium}=3molCa*(6.022*10^(23)particlesCa)/(1molCa) \\ \text{Particles of Calcium}=1.81*10^(24)particlesCa \end{gathered}](https://img.qammunity.org/2023/formulas/chemistry/college/t8oe438oimpgpm5mmutabdj3mgqn4wyopq.png)
To have 3.00 moles of Calcium will be required 1.81x10^24particles of Calcium