How many atoms are in 165 g of calcium?

What stress will shift the following equilibrium system to the left? n2(g) + 3h2(g) ⇌ 2nh3(g) adding more n2(g) adding more nh3(g) increasing the pressure of the system reducing the volume of the container

How many moles of lead are in 1.50 x 10^12 atoms of lead? could you explain the answer as well and not just give it to me i am refreshing for finals and i need to know how to do it

How many moles of cu are needed to react with 5.8 moles of agno3? cu + 2 agno3 → cu(no3)2 + 2 ag