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 ozone layer is a region within the stratosphere, extending from about 15 to 30 km (9 to 19 miles) above the Earth's surface.

It contains a high concentration of ozone (O3), a molecule made up of three oxygen atoms. 

The ozone layer plays a crucial role in protecting the Earth from harmful ultraviolet (UV) radiation from the sun, particularly UV-C and UV-B rays.

Explanation

Homeostasis is the set of metabolic reactions that maintain the internal environment of an organism, regulating factors.

Such as temperature, pH, blood sugar levels, and blood pressure.

Explanation

• Carbon dioxide (CO2) is a major greenhouse gas.
• It responsible for about 65% of the Earth's greenhouse effect.

Explanation

Opaque objects form sharp and dark shadows because they block all light from passing through, creating a clear and defined shadow.

Explanation

Explanation

The skin is considered the largest organ of the human body.

It covering an area of about 1.5-2 square meters (16-22 square feet).

It weighing around 3-4 kilograms (7-9 pounds).

Explanation

Vitamin C is essential for growth and repair of tissues in the body.

Protein formation: Vitamin C helps form collagen, a protein used to create skin, tendons, ligaments, and blood vessels.

Wound healing: Vitamin C helps heal wounds and form scar tissue.

Bone, teeth, and cartilage repair: Vitamin C helps repair and maintain bones, teeth, and cartilage.

Iron absorption: Vitamin C helps the body absorb iron. 

Vitamin C is also an antioxidant that promotes healthy teeth and gums.

A deficiency in vitamin C can lead to scurvy.

Explanation

• Fission is the splitting of a nucleus that releases free neutrons and lighter nuclei.
• The fission of heavy elements is highly exothermic which releases about 200 million eV compared to burning coal which only gives a few eV.

Explanation

A device that opposes the flow of electrons in electronic circuits is called a resistor.

It is a passive two-terminal component used to reduce current flow, divide voltage, and perform other functions by creating resistance.

Resistance is measured in ohms (Omega).