Answer: 
Explanation:
Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and 
for the reaction comes out to be negative.
Endothermic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat and for the reaction comes out to be positive.
As the heat is absorbed the reactants , the reaction is endothermic and for the given endothermic reaction will be +127 KJ
Answer:
organisms in rain water and the number of organisms in pond water because the dependant variable never changes
Explanation:
because the dependant variable never changes
Answer:
Actinium is a chemical element with the symbol Ac and atomic number 89. A soft, silvery-white radioactive metal, actinium reacts rapidly with oxygen and moisture in air forming a white coating of actinium oxide that prevents further oxidation.
CnH2n since the equivalent unsaturation is equal with 1
Z is the solvent, Y is soluble in water while X is insoluble in water.
<h3>Filtration</h3>
Filtration is a method of separation of substances based on particle size. Only a particular particle size can pass through the filter. The substance that remains in the filter is the residue while the substances that passes through the filter is called the filtrate.
From the observation in the question Z is the solvent, Y is soluble in water while X is insoluble in water.
Learn more about separation of mixtures: brainly.com/question/863988
