Question

Choose five advances in 20th century science that you think are the most important.

Answer 1

Einstein's special, 1905, and general, 1915, Theory of Relativity
Einstein's photo-voltaic effect, received Noble Prize for
Schrodinger's equation, about 1928, foundation of quantum mechanics
many applications of the above were used modern technology's such as atomic energy, solar cells, and advances in electronics.

Answer 2

In 1914 Garret Morgan invented the gas mask
In 1916 Henry Brearly invented stainless steel
The electron microscope was invented in 1939
In 1944 Synthetic cortisone invented by Percy Lavon Julian

It really depends on where you want to go with it, because there are so many options to choose from: airplanes, rockets (everything to do with outer space & space exploration), radio, television, antibiotics & vaccinations. There are just so many different options