Final answer:
Higher oxygen concentration leads to materials burning more intensely due to the increased reaction rate of the combustion process. A glowing splint used in a test will burst into flame when placed in a higher oxygen environment.
Step-by-step explanation:
Which of the following BEST describes the impact of higher oxygen concentration on combustion? The correct answer is A. Materials burn more intensely.
Oxygen is a critical component in the process of combustion, which is a redox reaction (a type of chemical reaction involving the transfer of electrons between two species). Combustion reactions require oxygen as one of the reactants, and the rate of the reaction increases with the concentration of oxygen. When a material such as a wooden splint is ignited and placed into a higher oxygen environment, the reaction rate increases significantly compared to that in normal air, which is about 20% oxygen. In an atmosphere with a higher oxygen concentration, combustion is not only more intense but can also occur at a faster rate, leading to a more vigorous and hotter fire. This is exemplified by the glowing splint test; when a glowing splint is introduced to an environment with a higher oxygen concentration, it will burst back into full flame due to the increased reaction rate.