Explanation

Earth is the densest planet in the solar system, with an average density of 5.52 g/cm³.

Its high density is due to a large iron-nickel core and rocky mantle.

Saturn is the least densest planet in the solar system.

Explanation

The photosphere is the lowest layer of the Sun's atmosphere.

It is the specific part that is visible to the human eye from Earth.

The term literally means "sphere of light," as most of the Sun's visible light is radiated from this layer.

It is important to note that the Sun has no solid surface.

As it is a giant ball of gas (plasma).

So the photosphere serves as its effective visible boundary. 

Explanation

Vitamin A is a group of fat-soluble retinoids.

Its preformed version found in animal products is called Retinol.

It is essential for maintaining healthy vision, skin, and immune function.

Explanation

The main source of energy in stars is nuclear fusion.

It is the process of combining atomic nuclei (usually hydrogen nuclei) to form a heavier nucleus, releasing vast amounts of energy in the process.

This energy is what makes stars shine.

Explanation

The Fourth Dynasty of the Old Kingdom of Ancient Egypt is responsible for building the Great Pyramid of Giza.

It is also known as the Pyramid of Khufu.

The pyramid was commissioned by the pharaoh Khufu.

It was constructed during his reign (circa 2580–2560 BC).

His son, Khafre (who built the second-largest pyramid at Giza), and Menkaure (who built the smallest of the three main pyramids) were also Fourth Dynasty pharaohs.

Explanation

Kill Devil Hills, near Kitty Hawk, North Carolina.

Date: December 17, 1903.

Pilot: Orville Wright was at the controls for the first flight.

Details of the first flight: It lasted 12 seconds and covered 120 feet.

Later flights: The brothers completed three more successful flights that day, with the final one lasting 59 seconds and covering 852 feet. 

Explanation

Insulin is produced by the pancreas, which is an organ located behind the stomach.

The pancreas contains clusters of cells called the Islets of Langerhans, specifically the beta cells within these islets, which are responsible for producing insulin.

Insulin plays a crucial role in regulating blood sugar levels by facilitating the uptake of glucose into cells for energy production or storage.

When blood sugar levels rise after a meal, the pancreas releases insulin to help lower blood sugar levels by promoting the uptake of glucose into cells.

Explanation

Explanation

Explanation

Aconcagua, located in the Andes Mountains in Argentina.

It is the highest mountain outside of Asia.

It is with a summit elevation of approximately 6,961 meters (22,838 feet).

It is the highest peak in South America.

It is the second most prominent.

It is isolated peak in the world after Mount Everest.