Question

mendeleevs method for arranging the periodic table led him to add blank spaces to maintain the pattern he had discovered. which factors did he use to determine his arrangement?
□ atomic mass
□ chemical properties
□ atomic number
□ radioactivity

Explanation:

Mendeleev arranged elements based on atomic mass and chemical properties. Atomic number was not known at his time and radioactivity was also not a factor in his arrangement.

Answer:

atomic mass, chemical properties