What did the Bohr model assume about the motion of electrons? A. All electrons move in a circular orbit around the nucleus.
B. Electrons do not have a specific path around the nucleus.
C. All electrons move in a single cloud layer around the nucleus.
D. Electrons always remain in the same location around a nucleus.

A

Explanation:

Bohr proposed that an electron is found only in specific circular paths, or orbits, around the nucleus

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