(worth 10pts) What did Dmitri Mendeleev contribute to science? A. He arranged the first periodic table. B. He developed the first model of the atom. C. He discovered many unknown elements . D. He developed the first atomic theory

A. He arranged the first periodic table.

Explanation:

i think so it’s will be b yes i believe its

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.