Answer:
6.02×10²³ particles / 1 mol
Step-by-step explanation:
In this question the choices are missed.
For determine the particles of Na, in 0.25 moles we should know that the mole referrs to the Avogadro's number.
1 mol of anything contains 6.02×10²³ entities, that's why we should apply this conversion factor to find the final answer:
0.25 mol . 6.02×10²³ particles / 1 mol = 1.50×10²³ particles
In conclussion: 1.50×10²³ particles of Na are contained in 0.25 moles of Na