ICSE ICSE Class 7 - CISCE Question Bank Solutions

Write true or false

A natural change can also be a desirable change.

Write true or false

Deforestation is a man-made change.

Write true or false 

Decomposition of leaves is a fast change.

Write true or false 

Dissolving of solute in a solvent and rusting of iron are both physical changes.

Photosynthesis cannot take place at night.

Name two reversible changes.

Give two examples of periodic changes.

What are man-made changes ?

Sublimation is classified as a physical change. Why ?

Classify the following changes as physical or chemical.

A physical change is temporary. Explain.

State the Differences Between a Physical Change and a Chemical Change.

State the various conditions that favour the process of evaporation.

Solve this crossword by using the clues that follow-

Across
1. Energy in the form of sunlight is absorbed by the green plants in this process.
4. The reddish-brown substance formed over iron in the presence of oxygen and moisture.
5. This change is permanent and irreversible.
6. The process in which a solid directly changes into gaseous state.

Down
1 . It is the change that takes place in case of swinging pendulum of a clock. –
2. Occurrence of this is a non-periodic change as well as a natural change.
3. It is a physical change.

Make a list of different types of changes with example.

 Rust is a hydrated oxide of iron which is

Fill in the blank spaces by choosing the correct words from the given list.
List: amalgam, chlorine, gallium, sodium chloride, silver chloride    

A gas used to sterilisation of drinking water is ________

State the term.

The number of atoms present in a molecule of an element _________

Define: Atomic number

 Define: Atomic number