Nitrogen-16 has an original sample soze of 50.0grams. how much of the sample will remain after a total time of 28.52 seconds has passes?

You encounter a solution that is acidic and you decide to test it by adding a small amount of a strong acid. the ph lowers slightly but is approximately unchanged, and still remains acidic. what can you say about the solution? a. it is a buffer solution. b. it is not a buffer solution it is a strong acid solution. d. the solution has been neutralized. e. the solution has excess acid present

Compare and contrast physical changes with chemical changes.

Is a pencil falling to the floor anon contact force, a force, or a contact force