Q. Some scientist and discovery pairs are given below: 1.Bohr-Model of hydrogen atom 2.Einstein-Photoelectric effect 3.Chadwick-Neutron 4.De Broglie-Matter waves Which of the above pairs are correctly matched?

• A. 1, 2 and 3
• B. 2 and 4
• C. 1 and 2
• D. 1, 2, 3 and 4

Correct Answer: D