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

Amphoteric substances are those that can react with both acids and bases.

They can donate or accept protons (H+ ions), depending on the conditions.

Examples of amphoteric substances include water (H2O), amino acids, and certain metals like zinc and aluminum.

Explanation

Systematic errors are caused by faulty or improper functioning of instruments, or by a flaw in the experimental design.

These errors are consistent and repeatable, and can be identified and corrected.

Explanation

• The general formula for alkanes is CnH2n+2, where n is the number of carbon atoms in the molecule.
• This formula represents the saturated hydrocarbons, also known as paraffins.

Key Points:

• CnH2n is the general formula for alkenes
• CnH2n+1 is the general formula for alcohols

Explanation

Glucose (C6H12O6) is a type of carbohydrate, specifically a simple sugar or monosaccharide.

It is a vital source of energy for many living organisms, including humans.

Glucose is a primary component of many carbohydrates, such as starch, cellulose, and glycogen.