Explanation

• Ibn Zakariya Al-Razi is considered the father of Pediatrics (Child healthcare).
• He was a famous Muslim physician, philosopher, and scientist.
• Field: Medicine, Chemistry, Philosophy
• Known as: Rhazes
• Famous books: Al-Hawi, Kitab al-Mansuri

Last verified on 09-06-2026

Explanation

Hydrogen gas is H₂, molar mass ≈ 2.016 g/mol  

Moles = mass / molar mass  

= 8.064 g / 2.016 g/mol = 4.0 mol

So there are 4 moles of H₂ molecules.

Last verified on 09-06-2026

Explanation

• Iron (Fe) is a trace element required in very small amounts in the body.
• It is essential for forming hemoglobin in blood.
• It helps in oxygen transport in red blood cells.
• Other trace elements include: Zinc, Copper, Iodine, Manganese, Cobalt.

Last verified on 09-06-2026

Explanation

There are 3 main types of chemical bonds based on electron behavior.

1. Ionic bond → electrons are transferred (lost or gained).
2. Covalent bond → electrons are shared between atoms.
3. Metallic bond → electrons are delocalized (free-moving) in metals.

Last verified on 09-06-2026

Explanation

• Chemical energy is the energy stored in the bonds between atoms and molecules.
• It is released or absorbed during chemical reactions.
• Found in substances like food, fuel, and batteries.
• It is a form of potential energy stored in chemical bonds.
• It changes into other forms like heat or light when reactions occur.

Last verified on 08-06-2026