Why is a “spark” of energy required to begin the chemical reaction of burning a fossil fuel? What is another name for this spark of energy?

What is the equation for calculating rf values

An uncovered pot of water lies out in the sun. which statements correctly describe what happens at the surface of the liquid water? 1. the vapor pressure remains constant regardless of the water temperature. 2. the vapor pressure is produced by water molecules that have evaporated. 3. the vapor pressure increases as the sun heats the water in the pot. 4. evaporation stops once the vapor pressure reaches a certain point. 5. evaporation and condensation both occur on the liquid’s surface.

Asap a 50.0 ml soap bubble is blown in a 27.0°c room. it drifts out an open window and lands in a snow bank at -3.0°c. what is its new volume?