Question

What is reaction ? Give one example. ​

Answer 1

Answer:

Reactions are of two types :

Physical and Chemical

Explanation:

Chemical : A chemical reaction happens when one or more chemicals are changed into one or more other chemicals. Examples:

iron and oxygen combining to make rust

vinegar and baking soda combining to make sodium acetate, carbon dioxide and water

things burning or exploding

many reactions that happen inside living things, such as photosynthesis

electrochemical reactions when discharging or recharging batteriea

Physical reaction: physical change is a type of change in which the form of matter is altered but one substance is not transformed into another. The size or shape of matter may be changed, but no chemical reaction occurs.

All physical changes are reversible and their mass does not change. Some examples are changes of shape, changes of states, and passing electricity through a copper wire. Physical changes could be: melting, freezing, boiling/evaporating, condensing, deposition and sublimation.

All physical changes are reversible and their mass does not change. Some examples are changes of shape, changes of states, and passing electricity through a copper wire. Physical changes could be: melting, freezing, boiling/evaporating, condensing, deposition and sublimation.Many physical changes also involve the rearrangement of atoms most noticeably in the formation of crystals. Many chemical changes are irreversible, and many physical changes are reversible, but reversibility is not a certain criterion for classification. Although chemical changes may be recognized by an indication such as odor, color change, or production of a gas, every one of these indicators can result from physical change.