Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Washing: Clothes should be washed regularly with soap or detergent to remove dirt, sweat, and germs. Clean clothes keep us healthy and prevent skin infections.
Drying: White clothes can be dried in direct sunlight as it acts as a natural bleach and kills germs. Colored clothes should be dried in the shade to prevent their colors from fading.
Ironing: After drying, clothes should be ironed to remove wrinkles and make them look neat and tidy.
Storing: Woolen and silk clothes need special care. They should be stored in boxes or cupboards with naphthalene balls () or dried neem leaves to protect them from insects like moths and silverfish.
Mending: Small tears or loose buttons should be fixed (mended) immediately to prevent the damage from getting worse.
Dry Cleaning: Delicate clothes like expensive silk sarees or woolen coats are often cleaned using chemicals instead of water, a process known as dry cleaning.
📐Formulae
💡Examples
Problem 1:
Why are naphthalene balls () kept in between woolen clothes when they are stored for a long time?
Solution:
To protect the clothes from insects.
Explanation:
Woolen and silk are natural fibers that insects like silverfish and moths like to eat. Naphthalene balls () release a gas that keeps these insects away, ensuring the clothes remain undamaged.
Problem 2:
Rohan noticed his bright red T-shirt looked dull after being dried in the sun for several hours. What should he do next time?
Solution:
Dry colored clothes in the shade.
Explanation:
The ultraviolet (UV) rays from the sun can break down the chemical bonds in fabric dyes, leading to fading. Turning clothes inside out and drying them in the shade helps maintain the color intensity.
Problem 3:
What is the primary chemical used in homes to wash clothes, and what is its role?
Solution:
Detergent or Soap.
Explanation:
Detergents help water () mix with oil and dirt. When we rinse the clothes, the detergent carries the dirt away with the water, leaving the fabric clean.