Explanation

• Electron: Discovered by J. J. Thomson, 1897

Additional information:

• Proton: Discovered by Ernest Rutherford, 1919
• Neutron: Discovered by James Chadwick, 1932
• Atomic Model Proposed: Plum Pudding Model
• Significance: First subatomic particle discovered

Last verified on 16-01-2026

Explanation

Steel is more elastic than rubber because the ratio of stress to strain is more for steel.

This indicates that steel deforms less under the same amount of stress compared to rubber, making it more elastic.

Explanation

Energy is measured in units of kilocalories

One kilocalorie  is equal to 4.18 kilojoules.

The amount of energy a food contains per gram is known as its energy density,

So we can describe fat as more energy-dense than protein or carbohydrate.

Explanation

The SI unit of electric charge is the coulomb, represented by the symbol C.

One coulomb is the amount of charge that passes through a conductor carrying one ampere of current for one second.

It's also equal to the charge of about 6.24 quintillion electrons or protons.

Explanation

J.J. Thomson discovered the electron in 1897 through his experiments with cathode rays.

The proton was discovered by Ernest Rutherford.

The neutron was discovered by James Chadwick.

Explanation

• Nitrogen makes up about 78% of the Earth’s atmosphere.
• Oxygen is about 21%,
• Other gases like argon and carbon dioxide are in very small amounts.

Last updated by NA on 28April 2026

Explanation

The ampere, symbol A, is the SI unit of electric current.

It is defined by considering the fixed  value of the elementary charge e as 1.602 176 634 x 1019,

where the unit C is equal to As and the second is defined by Δν Cs.

Explanation

The intensity of an earthquake is measured by the Richter scale.

It quantifies the energy released.

It was developed in 1935.

The Richter scale is used in seismology, the study of earthquakes.

Explanation

• There are around 639 skeletal muscles.
• The three main types of muscle include skeletal, smooth, and cardiac.
• The sartorius muscle is a thin, long, superficial muscle in the anterior compartment of the thigh.

Explanation

Silicon is a metalloid with properties ideal for controlling electrical current.

It's the most widely used material in semiconductor devices like transistors and chips.