1. Who invented Bleaching Powder ?

Answer: Tennant of Britain in 1798

2. Who invented Safety Pin ?

Answer: Walter Hunt of U.S.A. in 1849

3. Who invented paper ?

Answer:

Cai Lun

4. Who invented Circulation of blood ?

Answer: William Harvey of Britain in 1628

5. Who invented Air Conditioning ?

Answer:

Willis Carrier in 1902

6. Who invented Vitamin A ?

Answer: Mc Collum and M.Davis of U.S.A. in 1913

7. Who invented Biochemistry ?

Answer: Jan Baptista Van Helmont of Belgium in 1648.