An element from each of two compounds switch places. Example: compound + compound ⇒ compound + compound
Chemical reactions are processes in which substances change into other substances. A chemical reaction takes place if one or more of these occur: Color changes - Different combinations of molecules reflect light differently. A color change indicates a change in molecules. Heat content changes- In all chemical reactions, the heat content of the reactants and the heat content of the products is never the same. Sometimes the difference is great and can be easily detected. At other times, the difference is slight and more difficult to detect. Gas produced - Whenever a gaseous product forms in a liquid solution, bubbles can be seen. A colorless gas produced in a reaction of solids is much harder to detect. Precipitate forms- Precipitates are insoluble products formed by a reaction taking place in a liquid solution. This insoluble product will eventually settle to the bottom, but might immediately appear by turning the clear solution cloudy.
The relationship between the mass and the energy is given by Einstein formula as :
m is the mass of an atom
c is the speed of light
When an atom is formed, the energy gets absorbed. As a result mass will decrease as per Einstein's equation. So, the correct option is (c) "Energy is absorbed, so the mass is reduced".
