Question

one piece of evidence for the daltons atomic theory is the observation that
a all objects have mass.
b all objects have gravity.
c light travels as waves or particles.
d a compound always has the same proportions of different elements.

Explanation:

Dalton's atomic theory includes the law of constant composition, stating compounds have fixed element - to - element ratios.

Answer:

D. a compound always has the same proportions of different elements.