Changes Around Us Class 6 | worksheet
Changes Around Us Class 6. Download changes around us class 6 pdf worksheet based on the latest CBSE syllabus including MCQ on changes around us, define, long questions and more.
Changes around us class 6 notes ( Points to remember)
A Change refers to a noticeable difference in shape, size, colour, state, internal or any other property of a substance or an object.
Some changes produce a new substance while others do not. Many changes that take place around us occur themselves. Growing up of trees, shedding or leaves by plants, the occurrence of day and night etc. These changes are called natural changes. The changes that are brought about by humans are called man-made changes. Making of the dress by cutting and stitching fabric is an example of man-made change.
Reversible and irreversible changes.
Changes that can be reversed to get the original substance are called reversible change example melting of ice. Some changes cannot be reversed to get back the original substance these are called irreversible change, example of irreversible changes are human growth, making of curd from milk etc.
When water is heated, it changes into steam, this process is called vaporisation. If the steam is cooled down, it changes back into the water. This process is called condensation.
Physical change: Some changes in which only the physical properties of a substance change, but there is no change in its chemical composition is called a physical change. Example Evopration, boiling etc.
Melting of ice, evaporation of water are some common examples of physical changes that are reversible.
Not all physical changes are reversible. For example braking of glass, tearing of paper are physical changes that are irreversible.
Chemical changes: A change that is usually permanent in nature and leads to the formation of a new substance with composition and property different from those of the original substances are called chemical changes.
An example of chemical changes is when a piece of paper is burned, it changes into ash. The ash formed is a new substance and its composition and properties are different from paper. This burning of paper is an example of chemical changes.
when atoms of different elements combine to form compounds, a chemical change occurs.