Explanation

• Hygiene refers to the practice of maintaining cleanliness and purity to promote health and prevent disease.
• It includes habits such as washing hands regularly, bathing, brushing teeth, and wearing clean clothes.

Explanation

• Violet light has the smallest wavelength, approximately 380-450 nanometers (nm).
• While red light has the longest wavelength, approximately 620-750 nanometers (nm).
• The order of colors in the spectrum, from longest to shortest wavelength, is: Red, Orange, Yellow, Green, Blue, Indigo, Violet (ROYGBIV).

Explanation

A refracting telescope has two lenses:

1. A primary lens (objective) that collects and focuses light.
2. A secondary lens (eyepiece) that magnifies the focused light to form an image.

Explanation

• When animals and plants decay in the absence of air (anaerobic conditions), they produce a gas called biogas.
• Biogas is a mixture of methane (CH4) and carbon dioxide (CO2), with small amounts of other gases.
• It is produced through anaerobic digestion, a process in which microorganisms break down organic matter without oxygen.

Explanation

• Thermal Expansion is the natural increase in size of a substance as its temperature increases.
• It's a common phenomenon in solids, liquids, and gases.

Explanation

• A change in physical appearance or state of a substance, such as a change in shape, size, color, or phase (solid, liquid, gas), is called a Physical Change.
  

The are examples of Physical Changes:

• Melting (ice cream, wax, chocolate, ice and change from solid to liquid)
• Phase changes (boiling, freezing, condensation)
• Crushing (chalk)
• Tearing (paper)
• Crumpling (aluminium foil)
• Stretching (rubber band)
• Mixing (sugar in water)
• Dissolving (sugar, salt in water)
• Moulding (clay, metals)
• Slicing (fruit)
• Forming of frost (from water vapors)
• Transition to a gas (change from liquid to gas)
• Change of durability (change in texture or strength)
• Changes to crystal form (change in crystal structure)

Explanation

• Roots, stems, and leaves of plants can produce offspring through asexual reproduction.
• It involves the growth of new individuals from vegetative parts of the parent plant.

This can occur through:

• Roots: adventitious roots, root cuttings
• Stems: stem cuttings, runners
• Leaves: leaf cuttings, leaf propagation

Explanation

• Navigation satellites are used for identifying the location of objects on Earth.
• Example: GPS (Global Positioning System) for navigation.

Explanation

• A mirror with a reflecting surface that bulges outwards, like the back side of a spoon, is called a Convex Mirror.
• This type of mirror is used in applications such as security mirrors, rear-view mirrors, and surveillance mirrors, as it provides a wider field of view.

Explanation

• Filtration is a process used to separate insoluble solids from a mixture by passing the mixture through a filter.
• Which traps the solids and allows the liquid to pass through.