Compute the mass percent of carbon, hydrogen, nitrogen, and oxygen in caffeine, c8h10n4o2

Melting 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.

How many moles of potassium are needed to react completely with 12.8 moles of magnessium bromide?

What are the coefficients that will balance the skeleton equation below? n2 + h2 → nh3