6. How many mL of 0.1 M HCl should be added to 100 mL of a 0.2 M solution of tris base to make a buffer of pH 7.8

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.

the answer is 0.42 is that is an option. this question provides no info

nuclear fission produces elements that are heavier than helium.

the elements that are used in nuclear fission and their products are much heavier than helium.