Characteristics of a chemical change: 1) It is a permanent change. I.e . It can not be easily reversed. 2) It gives rise to the formation of new substances, which have properties entirely different from the starting materials. 3) The heat evolved or absorbed in a chemical reaction is quite high. 4)For example, element oxygen in the gaseous form combines with gaseous hydrogen element, to form a new substance i.e. Water. Hydrogen is inflammable and oxygen helps in burning, yet water can be used to put out fire!
Chemical changes are extremely important to our everyday life. Infact chemical changes or reactions are key to several of our daily tasks. It helps us in our kitchen with cooking and baking. E.g chemical reaction of baking soda while baking cookies. It also helps us with our cleaning. E.g Chemical reaction of detergent particles on stains. Thus, without chemical reactions we will not be able to perform our daily routine tasks.
There are two types of scientific changes/reactions, a chemical change is a change where it cannot be turned back, like burning paper and the ash can't be turned back. The other is a physical change where the change can be turned back, e.g. Dissolved salt can be evaporated and returned to its original form
-There is generally change in colour of reacting species
e.g. In rusting of iron nails rust is brown where as nails are black
-physical state of substance changes
-gas may be evolved
-it is of permanent nature and can not be reversed
-in most of chemical reactions the temperature changes
It is important for the lifecycle to create another component.
Well, a chemical change is when a change takes place, and changes its looks AND composition of an object. A chemical change usually stays like that, and you can't get it back to how it started originally very easily. I am learning about this in science right now.
Chemical occurs when a substance is transformed into another substance with a totally different composition and properties