Which of the following was not part of the Atomic Emission Spectrum experiment? Electrons are in fixed energy levels in an atom.

It helps to explain the phenomenon of the northern lights.

Electrons move up or down levels when energy is added or released.

Protons and neutrons are in the nucleus of the atom.

it is the most commonly accepted one

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