John Dalton
Although the concept of the atom dates back to the ideas of Democritus, the English meteorologist and chemist John Dalton formulated the first modern description of it as the fundamental building block of chemical structures.
Answer:C
Explanation: The mass is still the same even though they took it apart.
It would be the needle pressure gage temp check
Answer: This is because the number of shell increases .
Explanation: On moving from left to write on the periodic table the reactivity of non metals increases because number of shells increases and the force with which the nucleus hold electrons decreases.