Explanation

• If an object absorbs all seven colors of light (i.e., all the wavelengths of visible light), it appears black.
• This is because no light is being reflected, and our eyes perceive the absence of light as black.
• When an object reflects all the component colors of light, it appears white.

Last verified on 18-03-2026

Explanation

• Security mirrors are typically convex mirrors.

The examples of concave mirrors:

• Cosmetic mirrors (makeup mirrors)
• Dentist mirrors
• Car headlight mirrors

Last verified on 18-03-2026

Explanation

• A kaleidoscope is an optical instrument that creates symmetrical, colorful multiple images using mirrors and colored objects.
• When rotated, it continuously forms new patterns of images.
• Commonly used for educational purposes and toys.

Last verified on 18-03-2026

Explanation

• Reflection occurs when light bounces back from a surface instead of passing through it.
• Shiny or smooth surfaces like mirrors produce clear and regular reflections.
• This principle is used in mirrors, periscopes, and optical instruments.

Last verified on 18-03-2026

Explanation

• A saturated solution contains the maximum amount of solute that can dissolve at a given temperature.
• Any additional solute added will remain undissolved.
• Example: Sugar in water at room temperature reaches saturation when no more sugar dissolves.
• If a solution contains less solute than the maximum, it is called unsaturated.

Last verified on 18-03-2026

Explanation

• Crystallization (or recrystallization) is the primary technique used for the purification of solid compounds

Important points:

• It is used to remove impurities from solid substances.
• The impure solid is dissolved in a suitable solvent, then crystals of the pure compound form on cooling.
• It is commonly used in organic chemistry for the purification of solids.

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

• 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