Question

1. using his periodic table, mendeleev was able to — discover new elements form new types of matter create artificial elements predict the properties of unknown elements clear all

Explanation:

Mendeleev's periodic table arranged elements by atomic mass and predicted properties of undiscovered elements based on periodic trends. He didn't discover new elements with it directly, nor form new types of matter or create artificial elements using it. His key achievement was prediction of unknown elements' properties.

Answer:

D. predict the properties of unknown elements