Explanation

• Hydrogen is the lightest gas in the periodic table with atomic number 1.
• Its low density allows balloons to float in air.
• Used in party balloons, airships, and some scientific experiments.

Last verified on 18-03-2026

Explanation

• Sublimation is the process where a solid changes directly into gas without passing through the liquid state.
• It is used to purify solids that can vaporize easily, leaving impurities behind.
• Common examples include iodine, camphor, and naphthalene.

Last verified on 18-03-2026

Explanation

• A mixture contains two or more substances physically combined, which can be separated by physical means.
• Examples include sharbat, tea, steel.
• Common salt (NaCl) is a pure compound, not a mixture.

Last verified on 18-03-2026

Explanation

• Animal cells do not have chloroplasts, as they are not capable of photosynthesis.
• Animal cells also do not have a cell wall, unlike plant cells and some other organisms.

The components of an animal cell:

• Cell Membrane
• Cytoplasm
• Small Vacuole
• Nucleus
• Chromosomes

Last verified on 18-03-2026

Explanation

• Flowers are the reproductive structures of plants.
• It is responsible for producing seeds and facilitating sexual reproduction.
• They contain the male and female reproductive organs.
• They are essential for the production of fruits and seeds.

Last verified on 18-03-2026

Explanation

• Leaves are called the food factory of plants.
• They prepare food through the process of Photosynthesis.
• Chlorophyll in leaves absorbs sunlight to make food.
• Photosynthesis uses Carbon dioxide (CO₂), Water (H₂O), and Sunlight.
• Food produced is mainly Glucose, which provides energy to the plant.

Last verified on 13-03-2026

Explanation

• Chlorophyll is the green pigment responsible for photosynthesis in plants.
• It captures sunlight and converts it into chemical energy to make food.

• Plants use chlorophyll to produce glucose and oxygen through photosynthesis.
• Chloroplasts contain chlorophyll a and b, which absorb sunlight.

Last verified on 22-01-2026

Explanation

• Chromosomes are structures that carry genetic material (DNA) in cells.
• In animal cells, chromosomes are located in the nucleus, which controls cell activities and heredity.
• Number of chromosomes in humans: 46 (23 pairs)

Last verified on 18-03-2026

Explanation

Sum of 5 numbers = 5 × 12 = 60

Sum of 4 numbers = 4 × 13 = 52

Fifth number = 60 - 52 = 8

Last verified on 18-03-202

Explanation

Let the ages be x, x+4, x+8

Sum = x + (x+4) + (x+8) = 42

3x + 12 = 42

3x = 30

x = 10

Age of youngest child = 10

Last verified on 18-03-2026