Is it necessary to prepare sodium extract to detect nitrogen in urea ?

How much heat is released upon converting one mole of steam (18.0 g) from 100.0 ∘c to water at 25.0 ∘c? show work and constants, trying to figure out how it works. only given the heat capacity for steam and water so try to only use that

The characteristic of two different types of reactions are shown below. reaction a: electrons are gained by the atoms of an element. reaction b: protons are lost by the atom of and element. which statement is true about the atoms of the elements that participate in the two reactions? a: their identity changes in both reaction a and b. b: their identity changes in reaction a but not b. c: their identity changes in reaction b but not a. d: their identity remains the same.

In the millikan oil drop experiment they determined that every drop had a charge which was a while number multiple of -1.60x10^-19. if a drop has a total charge of -9.60x10^-19 then how many excess electrons are contained within the drop?