Which of the following observations would support the claim that as plants absorb sunlight to make food they release oxygen into the environment?
A. Oxygen concentration in the atmosphere was much higher millions of years ago when different plans existed.
B. When plants are kept in skilled environment the concentration of carbon dioxide steadily goes down.
C. Plants that are kept under conditions of total darkness want to grow normally and eventually will die.
D. The oxygen concentration in a pound with many plants increased during the day and decreases at night and on cloudy days.
Please help

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.

the correct answer is b. a strong acid completely dissociates to its ions when dissolved in water. completely dissociates to and ions. a is incorrect because does not fully ionize to and ions and some remain as the compound . c and d are incorrect because, and do not fall into the category of bronsted lowry acids. a bronsted lowry acid is a proton donor and since both molecules do not have a proton to donate they are not bronsted lowry acids. likewise,   if we use the lewis acid definition, they cannot be acids. a lewis acid is an electron pair acceptor. both and have a complete octet so can not accept any electrons which disqualifies them as acids.