TRUE OR FALSE Measurement of the position and velocity of a particle cannot be measured simultaneously with the same precision and accuracy.

True.

Explanation:

To describe the problem of trying to locate a subatomic particle that behaves  like a wave, Werner Heisenberg formulated what is now known as the Heisenberg  uncertainty principle: it is impossible to know simultaneously both the momentum p  (defined as mass times velocity) and the position of a particle with certainty.

Making measurement of the momentum of a particle more precise means that the position must become correspondingly less  precise. Similarly, if the position of the particle is known  more precisely, its momentum measurement must become less precise.

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

if it's not useful, feel free to report for mistake in answer.

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