An experiment requires 15.0 ml of a 0.100 m solution of hcl. if you have a 12.0 m hcl stock solution in the laboratory, how would you prepare enough 0.1 m solution to run at least 3 experiments?

Missing question: 

A. add 0.833 mL 12 M HCl stock solution to 99.167 mL water. 

B. add 0.833 mL 12 M HCl stock solution to 49.167 mL water. 

C. add 0.833 mL 12 M HCl stock solution to 199.167 mL water.

c₁ - original concentration of the solution, before it gets diluted.

c₂ - final concentration of the solution, after dilution.
V₁ - volume to be diluted.
V₂ - final volume after dilution.
c₁ · V₁ = c₂ · V₂.
c₁(HCl) = 12.0 M.

c₂(HCl) = 0.100 M.

V₂(HCl) = 3 · 15.0 mL = 45.0 mL; for three experiments.

V₁(HCl) = c₂ · V₂ / c₁.

V₁(HCl) = 0.375 mL.

Make proportion: 0.375 mL : 0.833 mL = 45 mL : V.

V = 100 mL.

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.

qualitative observation deals with data that can be observed with our senses: sight, smell, touch, taste, and hearing. they do not involve measurements or numbers. for instance, colors, shapes, and textures of objects are all qualitative observations.