Abiologist wants to know which fertilizer will result in the tallest pea plants. a chemist wants to know how much energy is required to change liquid water into water vapor. a geologist wants to know which type of soil is most permeable to water. a physicist wants to know what type of material reflects the most light.
which of the following methods can best be used by all of these different scientists to answer their individual questions?
a.
performing a controlled experiment
b.
drawing a diagram as a model
c.
using popular magazines as reference materials
d.
taking a survey of their fellow researchers

i wish i could but this one is weird give me abc and i can solve it.

i think its 100.

hope this !

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol