The ability of an atom to bond with neighboring atoms and be involved in chemical reactions depends on thenumber of electrons in its outer (valence) shell. energy level of its electrons. number of protons plus the number of neutrons. total number of electron shells present in the atoms. number of electrons in relation to the number of neutrons.

give me abc and i will get it for u.

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