Explanation

The most stable metals, such as gold and platinum, do not corrode easily

because they do not lose electrons easily.

while

Metals placed higher in the reactivity series, such as iron, zinc, etc., get corroded very easily

Explanation

An atomic bomb is based on the nuclear reaction known as nuclear fission,

A heavy atomic nucleus splits into two or more lighter nuclei, releasing a large amount of energy in an uncontrolled chain reaction.

The bombs dropped on Hiroshima and Nagasaki were examples of nuclear fission bombs, utilizing uranium-235 or plutonium-239 as the fissionable material. 

Explanation

• Au comes from the Latin word aurum, meaning "gold" (from "glowing dawn")
• Atomic number: 79
• Belongs to group 11 
• Category: transition metal

Additional information:

• Atomic mass: 196.97 u
• Melting point: 1,064°C
• Boiling point: 2,856°C
• Density: 19.3 g/cm³ (very heavy)

Explanation

Iron is the most used metal in construction, machinery, and tools.

Its alloy, steel, is the backbone of modern industry.

Explanation

Diamond and graphite are two allotropes of carbon:

As allotropes, they are different structural forms of the same element, carbon, which exhibit distinct physical properties due to their unique atomic arrangements

Explanation

Lead is commonly used as a shield against gamma rays.

Due to its high density.

It effectively absorbs and blocks gamma radiation.

Explanation

Limestone is a Sedimentary Rock, Stratified Rock, Aqueous Rock.

Limestone consists of calcium carbonate,

Which has the chemical formula CaCO3.

Calcium carbonate is a chemical compound

It is a common substance found in rocks as the minerals calcite

RK11-12-22

Explanation

Argon is a commonly used gas used to fill incandescent light bulbs.

It increases bulb life by preventing the tungsten filaments from deteriorating too quickly.

Other gases are also used in lighting such as:

• Helium
• Neon
• Nitrogen
• Krypton

Explanation

The two most common elements in the Earth's crust are:

• Oxygen (O) – about 46.6% by weight
• Silicon (Si) – about 27.7% by weight

Together, they form most of the silicate minerals, which make up the majority of the crust. 

Last updated 14-feb-2026

Explanation