Which subatomic particles are located in the nucleus of a carbon atom?
(1) protons, only
(2) neutrons, only
(3) protons and neutrons
(4) protons and electrons

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 answer to this question is 3.