Discovery School - 100 Greatest Discoveries - Chemistry
1. Oxygen (1770s) Joseph Priestley discovers oxygen; later, Antoine Lavoisier clarifies the nature of elements. Priestley produces oxygen in experiments and describes its role in combustion and respiration. Then, by dissolving fixed air in water, he invents carbonated water. Priestley, oblivious to the importance of his discovery, calls the new gas "dephlogisticated air." Lavoisier gives oxygen its name and correctly describes its role in combustion.
1. Microorganisms (1674) Microscope lens grinder Anton Van Leeuwenhoek accidentally discovers microorganisms in a drop of water. He observes sperm, bacteria and red blood cells.
2. The Cell Nucleus (1831) While studying an orchid, botanist Robert Brown identifies a structure within the cells that he terms the "nucleus."
3. Archaea (1977) Carl Woese discovers bacteria are not the only simple-celled prokaryotes on Earth. Many of the organisms classified in the new kingdom of Archaea are extremophiles.
The Curious Adventures of Sydney and Symon in: Water Wonders
The Curious Adventures of Sydney and Symon in: Water Wonders gives elementary school children the opportunity to tap into their curiosity and explore math and science while discovering the joy of reading and writing at the same time.
Water. We drink it. We cook with it. We wash with it. We can't live without it. Most of us don't think about it much. But it is not there for everybody, and our world is changing fast. We have to think very carefully about water, and about our use of it.
Water is vital to all life on Earth and covers nearly three-fourths of our planet's surface. Where does it come from? Will we use it up eventually? In The Water Cycle, students learn that the Earth has the same water supply today as it did millions of years ago. Examine the amazing process by which water is continually recycled and transported from place to place through evaporation, condensation and precipitation. Also find out how energy from the Sun drives the water cycle and how the atmosphere prevents water from slipping away from Earth.
