Who was the first known contributor to the atomic theory? select one: a. thomson b. bohr c. dalton d. democritus

It would be D Democritus
He contributed in around 460-370 BC
Whereas the others contributed much later from around 1700's - 1900's

Your answer is c. explanation: plasma  is the fourth state of matter, derived from the gaseous state of matter.  plasma  can contain free  electrons  and/or  ions. while  plasma is never neutral, it can either be positively or negatively charged.  gases, however, are electrically neutral.

    5.5 n======    assuming that      we have      m = 0.145 kg    a = 38 m/s²therefore    5.51 n, but two significant figures.final answer: 5.5 n