Which of these parts of dalton's atomic theory still holds true? * a. all atoms of the same element are identical. b. atoms can chemically combine in simple, whole number ratios. c. atoms have three parts. d. matter is made of tiny, indivisible particles called atoms.

The answer is; B

Atoms cannot be broken up in chemical reactions and react in whole number ratios. However, atoms can be split in radioactive reaction into subatomic particles (therefore atoms are not indivisible as Daltons stipulated). Atoms of the same elements can also vary in mass number (hence elements can have several isotopes).  

u i forgot the answer?

oxygen, selenium, tellurium, and polonium.

they're all from the same group as sulfur (group 16).