Explanation:
Once solid ammonium nitrate interacts with water, the molecules of polar water intermingle with these ions and attract individual ions from the structure of the lattice, that actually will break down. E.g;-NH4NO3(s) — NH4+(aq)+ NO3-(aq) To split the ionic bonds that bind the lattice intact takes energy that is drained from the surroundings to cool the solution.
Some heat energy is produced once the ammonium and nitrate ions react with the water molecules (exothermic reaction), however this heat is far below that is needed by the H2O molecules to split the powerful ionic bonds in the solid ammonium nitrate.
Hence, we can say that the dissolution of ammonium nitrate in water is highly endothermic reaction.
Answer:
group 8 of the periodic table
Explanation:
Answer:
gold wire (Au)
Explanation:
A substance that cannot be separated or broken down into simpler substances by chemical means is an element.
Between the given options only gold wire is an element, Au.
A way of knowing that it is an element is noticing that its formula is a single symbol which corresponds to an element found in the periodic table, unlike a combination of said symbols (like NaCl or H₂O).
Temperature. Water is an example. When water is at room temp. its liquid. When water is at boiling temp. It is a gas. And when water is at freezing temp. Its a solid.
Explanation:
(a) The mass of an object remains the same always. It is independent of its location. In this case, an iron nail is ground into powder. It means that its mass will remain unchanged. Hence, (a) is the correct option.
(b) Whenever there is a change of color of an object, a chemical reaction occurs. It shows that a reaction happens there. In this problem, a paper turns yellow-brown upon exposure to sunlight. A chemical reaction takes place there. Hence, (b) is the correct option.
