Explanation

• An atom typically has an equal number of electrons and protons.
• They are equal in number to the atomic number (Z) of the element.
• This number is unique to each element and determines the properties of the element.

Explanation

• Convection is the mode of heat transfer that occurs when a fluid (such as a gas or liquid) moves and carries heat energy from one location to another.
• This transfer of heat occurs due to the bulk motion of the fluid.

Explanation

The rate of evaporation can be increased by:

• Decreasing atmospheric pressure
• Increasing temperature
• Decreasing humidity
• Increasing the surface area of the liquid

Explanation

Mitosis is a type of cell division that involves the replication of a cell's DNA and the division of the cell into two daughter cells. It is essential for:

• Growth: Mitosis allows an organism to grow and develop by increasing the number of cells.
• Repair: Mitosis helps replace damaged or dead cells with new ones.
• Asexual reproduction: Mitosis enables asexual reproduction, where an organism produces offspring that are genetically identical to the parent.

Explanation

Root hairs are thin, hair-like structures that extend from the roots of plants, increasing the surface area for absorption of water and nutrients from the soil. They play a crucial role in:

• Absorbing water and minerals
• Anchoring the plant in the soil
• Facilitating the uptake of nutrients

Explanation

• Inertia is the tendency of an object to resist changes in its motion.
• As described by Newton's First Law of Motion (also known as the Law of Inertia).
• This means that an object at rest will remain at rest, and an object in motion will continue moving in a straight line, unless acted upon by an external force.

Explanation

The distance traveled by a body in unit time is called the speed of the body.

S.I. unit of speed is meter per second (ms−1).

ND11623

Explanation

The lens in the human eye is a convex lens, meaning it is thicker in the middle than at the edges.

This shape allows it to focus light rays convergently, creating a real image on the retina.

A convex lens is also known as a converging lens, as it converges light rays to a focal point.

Explanation

• Plants absorb Carbon Dioxide (CO2) during the daytime through tiny openings on their leaves called stomata.
• They use this carbon dioxide, along with water (H2O) and light energy from the sun, to produce glucose (C6H12O6) and oxygen (O2) through the process of photosynthesis.

Explanation

The stratosphere is the second layer of Earth's atmosphere as you go upwards, lying above the troposphere and below the mesosphere.

The layers of the Earth's atmosphere, in order from the surface, are:

1. Troposphere (up to about 12 km/7.5 miles)
2. Stratosphere (up to about 50 km/31 miles)
3. Mesosphere (up to about 85 km/53 miles)
4. Thermosphere (up to about 600 km/373 miles)