Traci Pedersen

Hippocrates was a physician who lived in ancient Greece and is credited with writing a code of ethics called the Hippocratic oath.

Reference The Mariana Trench is more than 7 miles (11 kilometers) deep. Although it is a toxic environment, some creatures of the deep thrive there.

Reference The Amazon River is a massive, intricate water system. It is by far the largest river on Earth in terms of volume and width.

Reference Learn about the many differences between prokaryotic and eukaryotic cells and how they evolved.

Polonium was a critical ingredient in the first atomic bomb and it's a suspected poison in more than one high-profile death.

Properties, sources and uses of the element indium.

Properties, sources and uses of the element radon.

The Everglades is an intricate system of subtropical wetlands, lakes and rivers in south Florida.

Properties, sources and uses of the element californium.

Properties, sources and uses of the element molybdenum.

Properties, sources and uses of the element hafnium.

Properties, sources and uses of the element rhodium.

Greenland is covered by a thick ice sheet. Scientists are growing extremely concerned that global warming is melting the ice too quickly.

Does adding sugar, aspiring or vinegar to the water keep your Christmas tree fresher longer? Try this experiment to find out.

Properties, sources and uses of the element vanadium.

Properties, sources and uses of the element gallium.

Properties, sources and uses of the element iodine.

The Mississippi River touches 31 U.S. states and two Canadian provinces and is one of the largest rivers in the world.

The Yangtze River is the longest river in Asia. It is approximately 3,915 miles (6,300 kilometers) long, the third longest river in the world.

The Nile River is considered the longest river in the world, but its actual length is a matter of debate.

Properties, sources and uses of the element calcium.

Properties, sources and uses of the element lead.

Properties, sources and uses of the element nickel.

Microbursts, also called downbursts, are powerful, localized columns of wind. They can cause just as much damage as a tornado.

Arsenic is a naturally occurring element with a reputation as "king of poisons" as well as the "poison of kings."