The water from the lake must first evaporate from the liquid state to the gaseous state and then condense in the air to form vapors.
The water molecules absorb energy while evaporating and release it when condensing. Their motion gets faster when they are evaporating and slows back down upon condensation.
Latent heat, also called the heat of vaporization, is the amount of energy necessary to change a liquid to a vapour at constant temperature and pressure. The energy required to melt a solid to a liquid is called the heat of fusion
Answer:
If anything but H2O were found, it would be evidence of a chemical change. Therefore, 4 is the only viable evidence that it was a physical change of H2O liquid to H2O gas.
Whenever any substance goes under chemical change so any of the reaction will happen either both or multiple compounds will combine to produce combination reaction either one compound will decompose itself into 2 or more compounds or elements and last one is replacement reaction the either reaction is not even going to combination nor decomposition, So when a reaction like that happens it must replacement reaction.
Now the question is what's the condition required for it, so basically a chemical reaction when takes place it depends upon several factor on the basis of which we conclude products. The factors are Temperature,catalyst,reagents, either what is the mechanism of reaction, stability of reactants and stability of products and alot more.
During reaction sometimes gas forms and sometimes not yea and well that also depends on the chemical reactivity and stability of product sometimes product found itself most stable releasing the gas evolving so it's been done itself and sometimes we add catalyst and adjust the reaction to extract that gas and get desirable product manually.
I wrote all i know if sorry if this is not what you're looking for :(
You forgot to attach the text
BTW reduction is the action or fact of making a specified thing smaller or less in amount, degree, or size.
