I was very concerned by the article “Cloudy Outlook for Sunscreen Market” in the Nov. 28, 2022, issue of C&EN (page 13). The danger of skin cancer and the benefits of sunscreens in preventing skin ...

The processes like crystallisation, boiling, vaporisation, burning of colour, melting point, hardness etc, are called physical changes. These are reversible in nature. The processes like ...

Chemical Reactions: A chemical reaction is a process where the substances 8unbdergo a change in their chemical composition. The substances that enter the reaction are called reactants that are then ...

Living cells are sustained by countless chemical reactions that must be carefully regulated to maintain internal order and ...

Chemical reactions make new chemicals. Atoms are rearranged during a chemical reaction, but the number of atoms does not change. A catalyst is a substance that speeds up a chemical reaction. Catalysts ...