Which value gives the number of particles in 1 mol of a substance?

The number of particles (molecules or atoms) is: 6.022 x 10²³ particles (atoms or molecules).

1 mol of H₂O has 6.022 x 10²³ molecules.
1 mol of Al has 6.022 x 10²³ atoms. 

Only one reactant yields 2 or more products. meaning you will only have 1 product and it will break down into 2 or more products. eg. h2o -> h2 + o2