conclusion on changes around us
Answers
Answer:
THESE ARE THE THINGS WE CONCLUDED FROM THE CHAPTER CHANGES AROUND US
HOPE YOU FIND IT HELPFUL:
Characteristics of chemical changes:
Properties of products are different from the properties of reactants.
Most of the chemical changes are irreversible.
These changes always result in energy changes.
Reversible changes: These are the changes that can be reversed. For example, stretching of rubber.
Irreversible changes: These are the changes which cannot be brought back to its original state. For example, burning of paper.
Melting point: A constant temperature at which a solid starts melting. This temperature is called the melting point of that solid.
Freezing: A process in which liquid changes into solid form is called freezing.
Force: A push or a pull acting on a body which tends to change its state of rest or motion is called a force.
Natural changes: The changes which occur in nature on their own are called natural changes. For example, change of day and night, change of season.
Slow changes: The changes which take longer time to occur are called slow changes. For example, rusting of iron, tooth decay.
Changes: Many changes are taken place around us on their own, e.g., flowers bloom and then wither away. We can also bring a change, e.g., change in the size of a balloon by blowing air in it.
Contraction: A process in which an object becomes smaller or shrinks is called contraction.
Evaporation: A process in which liquid changes into vapour is called evaporation.
Expansion: A process in which an object becomes bigger in size, e.g., metals expand on heating.
Melting: A process in which a solid melts to become a liquid on heating is called melting.
Answer:
In our daily life, we observe many changes around us. Everything in this universe undergoes a change. These changes may be observed by us at school, home, playground, garden or any other place. For example, sudden change in weather, flowering of plants, melting of ice, ripening of fruits, drying of clothes, milk changing into curd, germination of seeds, cooking of food, rusting of iron, bursting of firecrackers etc., are the common changes that occur in day-to-day life.
The changes can bring about different kinds of alterations in the things around us. Some of the alterations brought about are permanent in nature, and hence, cannot be reversed. However, some alterations are brought about in position, shape, size or state of the things. These alterations are temporary in nature, and hence, can be reversed.