Which contains more molecules: a mole of hydrogen or a mole of chlorine

Neither.  

Step-by-step explanation:

A mole of particles contains Avogadro's number of particles. Thus,

A mole of hydrogen contains 6.023 × 10²³ hydrogen molecules.

A mole of chlorine contains 6.023 × 10²³ chlorine molecules.

A mole of hydrogen and a mole of chlorine contain the same number of molecules.

conduction is the transfer of thermal energy (heat in transfer) due to collisions between the molecules in the object. collisions between adjacent atoms and molecules transfer kinetic energy from the warmer to the cooler object. the objects must be in physical contact.

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.