22 December 2014, 09:23 PM ET
Since the late 1700s, the world's climate has been changing rapidly, mostly due to human causes.
22 December 2014, 09:01 PM ET
Properties, sources and uses of nitrogen, one of the most abundant gases in Earth's atmosphere.
22 December 2014, 08:50 PM ET
The black mamba is one of the fastest and deadliest snakes in the world. Two drops of its venom can kill a person.
18 December 2014, 11:04 PM ET
Cobras are large, venomous snakes with a trademark hood. They hiss and spit and can raise the upper part of their bodies high enough to look you in the eye.
18 December 2014, 10:54 PM ET
Prenatal genetic testing may diagnose any complications or developmental issues.
18 December 2014, 10:15 PM ET
There are three types of infections that can affect the inner of outer ear. Ear infections are most common in children.
18 December 2014, 06:06 PM ET
Properties, sources and uses of the element mercury.
17 December 2014, 11:15 PM ET
The consequences of global warming are expected to be far-reaching, long-lasting and, in many cases, devastating.
17 December 2014, 11:10 PM ET
Strep throat is a bacterial infection. It is very contagious and can lead to severe complications.
17 December 2014, 10:39 PM ET
About 300 million years ago, all the seven continents formed one massive supercontinent called Pangaea.
16 December 2014, 09:46 PM ET
Laryngitis is inflammation of the larynx (voice box). The swelling causes hoarseness and limits your ability to talk.
16 December 2014, 09:29 PM ET
Camel spiders are not spiders, and they don't eat camels — or people. These arachnids became infamous after the Gulf War.
16 December 2014, 09:12 PM ET
Properties, sources and uses of the element magnesium.
16 December 2014, 12:46 AM ET
Coral snakes are small, vibrantly colored, highly poisonous snakes found in Asia and in the Americas. When threatened, they make a popping sound with their cloacas — essentially a fart.
15 December 2014, 09:19 PM ET
Global warming is the gradual heating of Earth's surface, oceans and atmosphere.
12 December 2014, 10:47 PM ET
12 December 2014, 12:47 AM ET
Rattlesnakes are found throughout North and South America. Their distinctive rattle warns intruders to stay away!
12 December 2014, 12:25 AM ET
Humans have invented six devices that combine to make work easier. These six simple machines are the wheel and axle, the lever, the inclined plane, the pulley, the screw and the wedge.
11 December 2014, 10:47 PM ET
Properties, sources and uses of the element silver.
11 December 2014, 10:24 PM ET
Funnel-web spiders build funnels out of their webs. Some of these spiders are among the most venomous in the world.
10 December 2014, 10:44 PM ET
Swollen veins that bump out from beneath the skin are called varicose veins or spider veins. There are several causes, as well as several methods of treatment.
10 December 2014, 10:35 PM ET
Bedbugs are stubborn parasites that leave itchy and unsightly bites, though they don't transmit disease or pose any serious medical risk.
10 December 2014, 09:49 PM ET
Legends about flying serpents are worldwide, but are dragon tales based in fact?
10 December 2014, 09:16 PM ET
Garter snakes are some of the most widespread snakes in North America. They can be found from Florida to Alaska.
09 December 2014, 10:34 PM ET
A sonogram, or ultrasound scan, can help determine the sex of a baby, but using fetal ultrasound to create keepsakes is not recommended.
09 December 2014, 10:30 PM ET
Thick plates protected this massive dinosaur from predators.
08 December 2014, 09:46 PM ET
Stegosaurus' distinctive features make it one of the most recognizable dinosaurs.
08 December 2014, 08:59 PM ET
Appendicitis is inflammation of the appendix. It is a serious illness and can be life threatening if not treated in time.
08 December 2014, 08:53 PM ET
Cervical cancer symptoms, diagnosis and treatment options.
05 December 2014, 09:52 PM ET
Bariatric surgery is an operation on the stomach and intestine used to treat obesity.
05 December 2014, 09:51 PM ET
Sleep apnea is a condition in which people experience pauses in breathing, or shallow breathing, during sleep.
05 December 2014, 09:41 PM ET
Diabetes is a metabolic disease marked by high blood glucose, also known as blood sugar.