How are isotopes of the same element alike? Select all that apply. They have the same number of protons.
They have the same mass number.
They have the same number of neutrons.
They have the same atomic number.

the old alchemists made significant contributions to science even though there starting premises were off a bit. their conclusions after failure would steer them into better directions for investigation. science is no more than close observation and the initial mistakes result in rethinking and retrying experiments.

i think is conclusions.i think so