Advertisements
Advertisements
प्रश्न
What will you take into account while identifying the following?
A physical change in a substance.
Advertisements
उत्तर
Physical changes are those changes in which only the forms of substances get modified; the chemical natures and compositions of the substances involved are not altered.
Characteristics:
- No new substance is formed during a physical change.
- Most physical changes can be reversed easily.
- The chemical composition of a substance undergoing physical change remains the same.
संबंधित प्रश्न
Classify the following as chemical or physical change:
Making a fruit salad with raw fruits
Melting of solid (wax) is a physical change.
Fill in the blank
Heat is ________ by a gas during the process of condensation.
Two chemical substances X and Y combine together to form a product P which contains both X and Y X + Y P
X and Y cannot be broken down into simpler substances by simple chemical reactions. Which of the following statements concerning X, Y and P are correct ?
- P is a compound
- X and Y are compounds
- X and Y are elements
- P has a fixed composition
Change is the law of nature and occurs in our everyday life, at all times and in all places.
Differentiate between the following change with a suitable example.
Periodic and non-periodic change
Change is the law of nature which occurs in everyday life.
State when a substance [i.e. matter] undergoes a kind of change.
State which of the following pertain to – chemical changes.
- Substance retains its identity.
- The change is permanent.
- No new substance is formed.
- Is easily reversible.
- Produces one or more new substances by a change in its composition.
- The change is temporary.
- The composition and properties of the original substance are not altered.
Select the chemical changes from the following list of changes
Vaporisation of water into water vapour.
Give the reason why the following is considered as chemical changes.
Sulphur when burnt in air evolves a gaseous acidic product.
In a solution of salt in water, water is the solute
