Question

why did mendeleev leave blank spaces in his version of the periodic table? mendeleevs periodic table arranged elements in order of increasing atomic mass; spaces were left for elements not having the correct atomic mass. mendeleevs periodic table arranged elements in groups of similar chemical properties; spaces were left for elements not having a similar chemical property. mendeleevs periodic table arranged elements in order of increasing atomic mass; it was noticed that chemical properties repeated. mendeleev predicted an element had not been discovered to fit the space. done

Explanation:

Mendeleev arranged elements by increasing atomic mass and noticed periodicity in chemical properties. He left blanks for undiscovered elements that would fit the periodic pattern.

Answer:

Mendeleev’s periodic table arranged elements in order of increasing atomic mass; it was noticed that chemical properties repeated. Mendeleev predicted an element had not been discovered to fit the space.