Which of the following is an example of rapid combustion? (a) phosphorous in water
(b) burning of a matchstick
(c) reaction of methane and oxygen in the air
(d) reaction of methane and oxygen in insufficient air

Molecular iodine, i2(g), dissociates into iodine atoms at 625 k with a first-order rate constant of 0.271 s−1. part a part complete what is the half-life for this reaction?

Calculate the mass of 0.750 mol of the following substance. na3po4.

Use the drop-down menus to label each of the following changes p for physical change and c for chemical change. the substance changes to a new substance. the original substance can be recovered. the color changes. gas is produced and given off. the substance changes size, shape, or volume.