How many moles are in 2.91 x 10^22 molecules of Helium?

What does x represent in the formula for the compound xcl4?

Freezing and boiling are endothermic processes. this means that these processes absorb energy from their surroundings in order to occur. use this information and the data you collected in the phase change gizmo to describe what happens to the temperature of water when you boil it, then explain why this result occurs.

If a solution had a ph of 7 what is the solution