Dissolving salt in water is an example of a chemical change. The dissolution leads the salt to break into sodium and chlorine ions, so it alters its essential chemical properties. Even though boiling salt water ends up leaving behind a residue of salt, while the salt and water are together, the chemical processes change enough to be viewed as a chemical reaction.Continue Reading
Salt is formed out of the ionically bonded elements of sodium and chlorine; the fact that water molecules are polar, with a slightly positive charge on one end and a slightly negative charge on the other means that water has the power to break some of these ionic bonds. The polarity in the salt molecules mirrors that of the water molecules, making it even easier for the water to break up the salt molecules, causing the salt to dissolve.
The process of breaking up the salt molecules involves the matching of opposite magnetic poles. The hydrogen end of the water molecule takes on a slightly positive charge, attracting the slightly negative chloride end of the salt molecule. This attraction also takes place between the slightly positive sodium end of the salt molecule and the slightly negative oxygen end of the water molecule.Learn more about Chemistry
No, the rusting of iron is a chemical change because it is two substances reacting together to make a new substance. When iron rusts, iron molecules react with oxygen molecules to make a compound called iron oxide. Rusting would only be a physical change if iron molecules remained pure iron throughout the process.Full Answer >
Tarnishing is a chemical change that occurs when certain metals are exposed to air or other sources. The change, known as oxidation reaction, is what leaves behind the tarnish.Full Answer >
Chemical reactions occur when two molecules collide with each other in a certain orientation and amount of force, which causes a chemical change due to the breaking and forming of the bonds between the atoms. Bonds are broken and formed due to the movement and sharing of electrons between atoms without any change to the nuclei.Full Answer >
Toasting bread is a chemical change since changing the bread to toast cannot be reversed. A chemical change affects the very essence of the object since the substances available at the beginning of the process are no longer available after completion of the process.Full Answer >