Answer:
Democritus
Explanation:
He spoke about matter was made of tiny particles which moved in empty space
As the atomic radius decreases, it becomes harder to remove an electron that is closer to a more positively charged nucleus. ... They experience a weaker attraction to the positive charge of the nucleus. Ionization energy increases from left to right in a period and decreases from top to bottom in a group.
Your answer is D. You're Welcome
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