Changes Around us Change An act or process through which something becomes different. Common Changes: Change in color- Add black and white Grey Change in position- Sitting on a Chair Bed Change in shape- Foil- triangle, mold clay Change in size cut paper Change in temperature Summer Winter, open AC Change in state Water Ice Cube Water Reversible Changes The changes that can be reversed back to original form. Melting of Chocolate Ice turning into water Stretching of rubber band Melting of Butter Irreversible Changes The changes that can’t be reversed back to original form. Making omelette Conversion of milk to curd and cheese Baking a cake Burning Wood Reversible Or Irreversible Cutting of paper Molding clay into pot Baking clay pot Reversible Or Irreversible Reversible and Irreversible… Melting of wax Reversible Burning of wax & thread Irreversible IP Questions 5 Reversible changes 5 Irreversible Changes 2 Changes that are both Fast Change The changes that happen in seconds or minutes. Melting of Chocolate Slow Change The changes that take hours or days. Growth of a Person Stretching of rubber band IP Questions 5 fast changes 5 slow changes 5 fast & irreversible changes Periodic Change The changes that repeats itself after a fixed time interval. Melting of Chocolate Day and Night Time Stretching of rubber band Changes in phases of moon Changes in Season Non-Periodic Change The changes that does not repeats itself after a fixed time interval. Volcano Eruption Earthquake Growth of a Person Forest Fires Why Changes Occur Mixing Putting Pressure Why Changes Occur Cooling Heating Expansion Increase in size of an object when it is heated. Change in state of matter Melting of Chocolate Contraction Decrease in size of an object when it is cooled. Freezing Orange Juice Rim on Wheel Heating the rim makes it increase in size Fixing the rim on wheel Cold water contract the rim and it fix Other Examples Thank you….