Explanation

A Lewis base is a substance that donates a pair of electrons to form a coordinate covalent bond.

This means that a Lewis base is an electron pair donor.

Explanation

A biogeochemical cycle is the process by which elements are recycled through an ecosystem, passing through both living organisms (biotic factors) and non-living components (abiotic factors) like air, water, and soil.

This cycle involves the movement of elements like carbon, nitrogen, oxygen, and phosphorus through the environment and living things.

Explanation

Reproduction is the biological process by which new individuals are produced, ensuring the continuation and survival of a species.

It is a fundamental aspect of life, allowing species to perpetuate themselves, adapt to their environments, and evolve over time.

Explanation

Vitamin A is essential for proper vision, particularly in low light conditions.

It plays a critical role in the functioning of the retina, the light-sensitive tissue at the back of the eye.

Explanation

The dermis is the middle layer of the skin.

It contains a network of blood capillaries that supply oxygen and nutrients to the skin cells.

The dermis also contains hair follicles, sweat glands, and sebaceous glands.

Explanation

The kidneys are enclosed in a membrane called the peritoneum, which is a thin layer of tissue that lines the abdominal cavity.

The peritoneum supports and protects the kidneys, as well as other organs in the abdominal cavity.

Explanation

Question: A girl throws a small stone into a lake. Waves spread out from where the stone hits the water and travel to the bank of the lake. She notices that ten waves reach the side of the pond in a time of 5.0s. What is the frequency of the waves?

Answer: Frequency is defined as the number of waves (or cycles) per second. In this case, 10 waves reach the bank in 5 seconds, so:

Frequency = Number of waves / Time

= 10 waves / 5 s

= 2 waves/s

= 2.0 Hz

Explanation

Electric fields can be detected by electrons, which are charged particles that respond to the force exerted by the electric field.

Electrons will accelerate or decelerate in the presence of an electric field, allowing for the detection of the field.

Explanation

Resistivity is a property of the material itself, and is not a factor that affects the resistance of a specific conductor.

The resistance of a conductor depends on its length, cross-sectional area, and the material's resistivity.

Explanation

Aeroplanes fly in the troposphere, which is the lowest layer of the Earth's atmosphere, extending up to about 12 km (7.5 miles) above the Earth's surface.

The troposphere is where weather occurs, and it's the layer where aircraft operate, typically cruising at altitudes between 30,000 to 40,000 feet (9,100 to 12,200 meters).