Question

exam lesson name: chemistry
exam number: 700700rr
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question 6 of 20 :
select the best answer for the question.

1. the periodic table is based on an elements

○ a. atomic mass.
○ b. molecular mass.
○ c. atomic number.
○ d. molecular size.
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Explanation:

The periodic table arranges elements by atomic number (number of protons in the nucleus), as it provides a consistent and fundamental property for organization. Atomic mass was used in earlier versions but is not the basis now. Molecular mass and molecular size relate to molecules, not element arrangement.

Answer:

C. atomic number.