Complete combustion of a 0.70mol sample of a hydrocarbon gives 3.50mol of co2 and 2.80mol of h2o the molecular formula for the hydrocarbon is

d) a person who learns about the world by observing it.

explanation:

scientist are people who discover why and how things are done and made in the world.

it is the minimum amount of material needed to sustain a fission reaction.

critical mass is the minimum amount of fissionable material that must be assembled for a sustained fission reaction to take place. although two to three neutrons are produced for every fission, not all of these neutrons are available for continuing the fission reaction. if the conditions are such that the neutrons are lost at a faster rate than they are formed by fission, the chain reaction will not be self-sustaining.   at the point where the chain reaction can become self-sustaining, this is referred to as critical mass.

a redox reaction

explanation:

potassium metal is oxidized to potassium ion, and iodine is reduced to iodide ion, and we add (i) and (ii) together to eliminate the electrons.