Explanation

The human body contains traces of many elements, and approximately 99% of its mass is comprised of just six essential elements:

1. oxygen
2. carbon
3. hydrogen
4. nitrogen
5. calcium
6. phosphorus

Another five elements—

1. sulfur
2. potassium
3. sodium
4. chlorine
5. magnesium

Make up about 0.85% of the remaining mass, bringing the total of essential elements to 11

Explanation

Explanation

• The brain, situated in the cranial cavity is an important internal organ.
• It is the control centre of our body.
• It controls the movements and all that we do.
• The brain is protected by the skull.

Explanation

 Cyclohexane is an alicyclic compound. 

Alicyclic compounds are cyclic (meaning they form a ring) and saturated (meaning they only have single bonds between carbon atoms).

Cyclohexane fits this description as it is a six-membered ring with only single bonds connecting the carbon atoms. 

Explanation

Starch is a type of polysaccharide, which falls under the category of carbohydrates.

It is a complex carbohydrate made up of many glucose units and serves as an energy storage molecule in plants.

Explanation

 Ethene (also known as ethylene) is a naturally occurring plant hormone that plays a key role in fruit ripening.

It is commonly used commercially to artificially ripen fruits like bananas, tomatoes, and avocados. 

Explanation

Amphoteric nature​​ Aluminium oxide is an amphoteric substance, meaning it can react with both acids and bases

It is a chemical compound of aluminium and oxygen with the chemical formula Al2O3.

Explanation

A heterocyclic compound is a ring structure that contains at least one atom other than carbon in the ring.

Pyridine has a nitrogen atom in its ring structure, making it a heterocyclic compound. 

Explanation

Aluminum (Al) reacts with oxygen to form a thin protective oxide layer (Al₂O₃) that prevents further oxidation.

This is why it doesn’t react aggressively with oxygen after this initial reaction.

Explanation

The candela (cd) is the SI unit for luminous intensity, which measures the perceived brightness of a light source. 

Mole (a): This is the SI unit for the amount of substance. 

Kelvin (b): This is the SI unit for temperature. 

Ampere (d): This is the SI unit for electric current.