Explanation

• The telescope was first used for astronomical observations in the early 17th century.
• Galileo Galilei first used an improved telescope in 1609 to observe planets like Jupiter, Saturn, and Venus.
• He discovered four large moons of Jupiter (Io, Europa, Ganymede, and Callisto).

Last verified on 11-03-2026

Explanation

• A Telescope is an optical instrument used to observe distant objects such as stars, planets, and galaxies.
• It collects and magnifies light or other forms of electromagnetic radiation.
• The term “telescope” was coined in 1611 by the Greek mathematician Giovanni Demisiani.

Last verified on 10-03-2026

Explanation

The Nobel Prize for the discovery of the electron was awarded to J. J. Thomson in 1906.

He received the Nobel Prize in Physics for his investigations into the conduction of electricity in gases, which led to the discovery of the electron in 1897.

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Explanation

Antonie van Leeuwenhoek first observed yeast cells using his single-lens microscope in 1680. 

Explanation

Carolus Linnaeus  was a Swedish botanist,

He is widely recognized as the "Father of Taxonomy".

In the 18th century, he published his seminal work, Systema Naturae, in which he introduced a formal, hierarchical system for classifying and naming living organisms.

Explanation

Johann Dobereiner, a German chemist, introduced the concept of 'triads' in 1817

 Law of Triads, Groups of three elements with similar properties; middle element's atomic mass is average of others.

Explanation

Jean-Jacques Rousseau is called the Father of the French Revolution.

Born on June 28, 1712

Died on July 2, 1778, at the age of 66 years.

Explanation

Jean-Jacques Rousseau was born on June 28, 1712

Died on July 2, 1778, at the age of 66 years.

He is called the Father of the French Revolution.

Explanation

Oxygen was discovered in 1774 by English chemist Joseph Priestley,

He isolated it by heating mercuric oxide and called it "dephlogisticated air".

Oxygen was discovered independently by Carl Wilhelm Scheele (around 1772)

Explanation

HIV (Human Immunodeficiency Virus) was first identified in 20 May 1983

By researchers Luc Montagnier and Françoise Barré-Sinoussi in France.

Their discovery linked HIV to AIDS, leading to significant advancements in understanding and managing the disease.