Question

question 14 of 25
what did dmitri mendeleev contribute to science?

a. he discovered many unknown elements.

b. he developed the first atomic theory.

c. he developed the first model of the atom.

d. he arranged the first periodic table.

Explanation:

• Option A: Mendeleev didn't discover many unknown elements; he predicted properties of undiscovered elements based on his periodic table.
• Option B: The first atomic theory was developed by John Dalton, not Mendeleev.
• Option C: The first model of the atom (like the plum - pudding model or later ones) was not developed by Mendeleev.
• Option D: Dmitri Mendeleev is known for arranging the first periodic table of elements, organizing them by atomic mass and leaving spaces for undiscovered elements.

Answer:

D. He arranged the first periodic table.