Chemistry Discoveries — Set 2
Inventions · रसायन की खोजें · Questions 11–20 of 70
Who discovered Penicillin, the world's first true antibiotic, in 1928?
Correct Answer: C. Alexander Fleming
Alexander Fleming noticed that a mold called Penicillium notatum destroyed staphylococci bacteria in a petri dish. This accidental discovery revolutionized the treatment of infectious diseases globally. He shared the 1945 Nobel Prize in Medicine for this achievement.
The discovery of X-rays, which helped reveal chemical structures, was made by?
Correct Answer: C. Wilhelm Röntgen
Wilhelm Röntgen discovered this high-energy radiation while working with vacuum tubes in 1895. He took the first medical X-ray of his wife's hand, showing her bones and ring. He was the first person ever to be awarded the Nobel Prize in Physics.
Who is known for developing the modern concept of acids and bases involving proton transfer?
Correct Answer: C. Johannes Brønsted
Johannes Brønsted, alongside Thomas Lowry, defined acids as proton donors and bases as proton acceptors. This theory expanded the understanding of acid-base reactions beyond aqueous solutions. It remains a standard concept taught in high school chemistry today.
The discovery that the atomic number, not atomic weight, is the key to the periodic table was made by?
Correct Answer: D. Henry Moseley
Henry Moseley used X-ray spectroscopy to measure the charge of the nucleus in different elements. His work provided a firm physical basis for the arrangement of the modern periodic table. Tragically, he was killed in action during World War I shortly after his discovery.
Who discovered Hydrogen, referring to it as 'inflammable air'?
Correct Answer: B. Henry Cavendish
Henry Cavendish was the first to recognize hydrogen as a distinct substance in 1766. He also accurately determined the composition of the atmosphere and the density of the Earth. Hydrogen is the lightest and most abundant chemical element in the universe.
The 'pH scale' for measuring acidity was invented by which chemist?
Correct Answer: C. S.P.L. Sørensen
S.P.L. Sørensen introduced the pH scale in 1909 while working at the Carlsberg Laboratory in Denmark. The scale ranges from 0 to 14, with 7 being neutral. This invention simplified the way scientists express the concentration of hydrogen ions.
Which scientist discovered the 'Law of Definite Proportions' in chemical compounds?
Correct Answer: B. Joseph Proust
Joseph Proust proved that a chemical compound always contains exactly the same proportion of elements by mass. This law was fundamental to the development of modern atomic theory by John Dalton. It distinguishes true chemical compounds from simple physical mixtures.
Who discovered the noble gas Helium on Earth after it was detected in the Sun?
Correct Answer: B. William Ramsay
Sir William Ramsay isolated helium on Earth in 1895 by treating a mineral called cleveite with acids. He also discovered other noble gases like neon, krypton, and xenon. He received the Nobel Prize in Chemistry in 1904 for these discoveries.
The discovery of 'Vaccination' as a chemical/biological defense was pioneered by?
Correct Answer: D. Edward Jenner
Edward Jenner used cowpox material to create immunity to smallpox in 1796. His work is often called the foundation of immunology, a field that uses chemical interactions for immunity. Smallpox eventually became the first human disease to be eradicated globally.
Who discovered the process of Vulcanization, making rubber durable?
Correct Answer: D. Charles Goodyear
Charles Goodyear accidentally discovered that heating natural rubber with sulfur makes it resistant to temperature changes. This chemical discovery allowed for the widespread use of rubber in tires and machinery. Despite his massive contribution, he died in debt.