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How Do Pregnancy Tests Work?

There are many ways to find out if you’re pregnant. One is to wait and see. For those of us who are a little less patient, there’s the take-home chemistry kit known as a pregnancy test. But how do a little strip of paper and a few drops of urine tell you whether or not you’ve got a bun in the oven?
Season 5 Episode 64 Length 03:16 Premiere: 05/07/19

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Season 5 Episodes

How Do Antiviral Drugs Work?
S5 E99 Length 06:53 Premiere Date 05/11/20

The Early Plan to Fight COVID with the Polio Vaccine
S5 E98 Length 05:26 Premiere Date 05/01/20

Do Masks Stop COVID-19? (Yes! Here's Why)
S5 E97 Length 09:42 Premiere Date 04/17/20

How Did We Get COVID Vaccines So Quickly?
S5 E96 Length 05:37 Premiere Date 04/01/20

Can Soap Really "Kill" the Coronavirus?
S5 E95 Length 05:38 Premiere Date 03/18/20

The US Military Gave Out Shark Repellent For Years
S5 E94 Length 07:32 Premiere Date 01/10/20

Which of These Mushrooms Could Kill You?
S5 E93 Length 05:40 Premiere Date 12/23/19

11 Things You Can Do With Your Dead Body
S5 E92 Length 06:50 Premiere Date 12/18/19

Cartoon Chemistry!
S5 E91 Length 06:50 Premiere Date 12/13/19

How Miracle Berries Alter Your Taste Buds
S5 E90 Length 04:42 Premiere Date 12/04/19

Yule Log Chemistry Trivia - 4 Hours of Cozy Fireplace
S5 E89 Length 4:11:33 Premiere Date 12/02/19

Can You Cryogenically Freeze Your Body and Come Back to Life
S5 E88 Length 07:58 Premiere Date 11/27/19

The Science of J. Kenji López-Alt's Roasted Potato Recipe
S5 E87 Length 10:21 Premiere Date 11/22/19

World’s Deadliest (& Cutest) Animals
S5 E86 Length 08:42 Premiere Date 11/06/19

Where Did the Vampire Lore Come From?
S5 E85 Length 08:51 Premiere Date 10/31/19

How Do Blacksmiths Make Swords?
S5 E84 Length 05:11 Premiere Date 10/16/19

How to Make Magnetic Slime
S5 E83 Length 04:43 Premiere Date 10/09/19

Space Mirrors and Other Weird Ways to Fight Climate Change
S5 E82 Length 04:10 Premiere Date 09/25/19

We Tested Google’s Tips for Getting Stains Out
S5 E81 Length 16:02 Premiere Date 09/18/19

Is Superhero Strength Real?
S5 E80 Length 03:35 Premiere Date 09/10/19

How Much Does a Cloud Weigh?
S5 E79 Length 03:26 Premiere Date 09/05/19

Don't Mix These Things with Birth Control!
S5 E78 Length 05:30 Premiere Date 08/21/19

What Exactly Happened at Chernobyl?
S5 E77 Length 08:54 Premiere Date 08/15/19

Can a Fecal Transplant Save You From This Dangerous Bacteria
S5 E76 Length 04:16 Premiere Date 08/06/19

How Do We Fight the California Fires?
S5 E75 Length 06:26 Premiere Date 07/30/19

What Happens When You Overdose?
S5 E74 Length 05:42 Premiere Date 07/23/19

The Top 5 Strangest Poisons That Can Kill You
S5 E73 Length 04:48 Premiere Date 07/16/19

Can We Make Ocean Water Drinkable -- and Should We?
S5 E72 Length 04:13 Premiere Date 07/02/19

How Pee Helped Win the Revolutionary War (Maybe...)
S5 E71 Length 05:09 Premiere Date 06/25/19

What Does the Moon Smell Like?
S5 E70 Length 05:48 Premiere Date 06/19/19

What is Ringworm and How Do You Get Rid of It?
S5 E69 Length 04:11 Premiere Date 06/11/19

Could CBD Make You Fail a Drug Test?
S5 E68 Length 03:43 Premiere Date 06/04/19

What Causes Auroras?
S5 E67 Length 04:34 Premiere Date 05/29/19

Why is Carbon the Key to Life? (On Earth, Anyway)
S5 E66 Length 04:21 Premiere Date 05/21/19

That Fresh Cut Grass Scent is Really a Signal of Distress
S5 E65 Length 03:10 Premiere Date 05/14/19

How Do Pregnancy Tests Work?
S5 E64 Length 03:16 Premiere Date 05/07/19

How Does Pepper Spray Work?
S5 E63 Length 03:41 Premiere Date 05/01/19

How to Get Rid of Skunk Smell
S5 E62 Length 03:40 Premiere Date 04/23/19

How to Get Rid of Skunk Smell
S5 E62 Length 03:40 Premiere Date 04/23/19

Why Do Clothes Shrink in the Wash?
S5 E61 Length 04:15 Premiere Date 04/16/19

Why Do Clothes Shrink in the Wash?
S5 E61 Length 04:14 Premiere Date 04/16/19

White, Green, Black, and Oolong Tea: What's the Difference?
S5 E60 Length 04:32 Premiere Date 05/09/19

White, Green, Black, and Oolong Tea: What's the Difference?
S5 E60 Length 04:31 Premiere Date 04/09/19

Why Are Birds Different Colors?
S5 E59 Length 04:13 Premiere Date 04/02/19

Why Are Birds Different Colors?
S5 E59 Length 04:12 Premiere Date 04/02/19

These Two Women Changed Chemistry Forever
S5 E58 Length 04:59 Premiere Date 03/20/19

These Two Women Changed Chemistry Forever
S5 E58 Length 04:59 Premiere Date 03/20/19

Are We Running Out of Helium?
S5 E57 Length 04:35 Premiere Date 03/12/19

What's In Dog Food?
S5 E56 Length 05:37 Premiere Date 03/05/19

What's In Dog Food?
S5 E56 Length 05:37 Premiere Date 03/05/19

Can Mixing Cleaning Chemicals Kill You?
S5 E54 Length 04:30 Premiere Date 02/19/19

Can Mixing Cleaning Chemicals Kill You?
S5 E54 Length 04:30 Premiere Date 02/19/19

How Did the 80s Get Hair So Big?
S5 E53 Length 04:31 Premiere Date 02/12/19

The Perm
S5 E53 Length 04:24 Premiere Date 02/12/19

Is White Chocolate Actually White Chocolate?
S5 E52 Length 02:56 Premiere Date 02/05/19

Is White Chocolate Actually Chocolate?
S5 E52 Length 02:55 Premiere Date 02/05/19

Does Shaving Cream Do Anything?
S5 E51 Length 08:15 Premiere Date 01/30/19

Why Flamingos Are Pink and Hardcore
S5 E50 Length 03:32 Premiere Date 01/22/19

Why Flamingos Are Pink and HARDCORE
S5 E50 Length 03:32 Premiere Date 01/22/19

Citrus Scent DEBUNKED!
S5 E49 Length 03:48 Premiere Date 01/17/19

Citrus Scent DEBUNKED!
S5 E49 Length 03:48 Premiere Date 01/17/19

Can Plastic Be Composted?
S5 E48 Length 04:33 Premiere Date 01/09/19

Can Plastic Be Composted?
S5 E48 Length 04:32 Premiere Date 01/09/19

How Does Low-Dose Aspirin Work?
S5 E47 Length 04:27 Premiere Date 01/07/19

How Does Low-Dose Aspirin Work?
S5 E47 Length 04:27 Premiere Date 01/01/19

What Makes Kimchi So Delicious?
S5 E45 Length 04:39 Premiere Date 12/18/18

How is Kimchi Made?
S5 E45 Length 04:39 Premiere Date 12/18/18

Is Santa's Flame Resistant Suit Killing Him?
S5 E44 Length 03:53 Premiere Date 12/11/18

Is Santa's Flame Resistant Suit Killing Him?
S5 E44 Length 08:15 Premiere Date 12/11/18

Why Don’t Antarctic Fish Freeze to Death?
S5 E43 Length 04:11 Premiere Date 12/04/18

Why Don’t Antarctic Fish Freeze to Death?
S5 E43 Length 04:13 Premiere Date 12/04/18

Why Does Humidity Feel Gross?
S5 E42 Length 04:55 Premiere Date 11/27/18

Why Does Humidity Feel Gross?
S5 E42 Length 04:54 Premiere Date 11/27/18

How is Leather Made?
S5 E41 Length 04:03 Premiere Date 11/13/18

How is Leather Made?
S5 E41 Length 04:03 Premiere Date 11/13/18

Fact or Fiction: Uncooked Rice is Bad for Birds
S5 E40 Length 04:30 Premiere Date 11/06/18

Fact or Fiction: Uncooked Rice is Bad for Birds
S5 E40 Length 04:29 Premiere Date 11/06/18

Do Astronauts Need Sunscreen?
S5 E39 Length 05:03 Premiere Date 10/23/18

How Do You Catch Fruit Flies?
S5 E38 Length 03:16 Premiere Date 10/16/18

How Do You Catch Fruit Flies?
S5 E38 Length 03:16 Premiere Date 10/16/18

Tardigrades
S5 E37 Length 03:12 Premiere Date 10/09/18

Tardigrades
S5 E37 Length 03:11 Premiere Date 10/09/18

Turning the Boston Harbor into Actual Tea
S5 E36 Length 04:10 Premiere Date 10/02/18

How Much Tea Would it Take to Turn the Boston Harbor into It
S5 E36 Length 04:11 Premiere Date 10/02/18

What is Natto?
S5 E35 Length 04:46 Premiere Date 09/25/18

What is Natto?
S5 E35 Length 05:09 Premiere Date 09/25/18

Can Silver Nanoparticles Combat Your Stink?
S5 E34 Length 02:52 Premiere Date 09/18/18

Can Silver Nanoparticles Combat Your Stink?
S5 E34 Length 02:47 Premiere Date 09/18/18

What are Eye Boogers?
S5 E33 Length 01:47 Premiere Date 09/11/18

What are Eye Boogers?
S5 E33 Length 01:43 Premiere Date 09/11/18

How Does Double Acting Baking Powder... Doubly Act?
S5 E32 Length 02:23 Premiere Date 09/04/18

How Does Double Acting Baking Powder... Doubly Act?
S5 E32 Length 02:19 Premiere Date 09/04/18

How Plastic Recycling Actually Works
S5 E31 Length 03:01 Premiere Date 08/28/18

How Plastic Recycling Actually Works
S5 E31 Length 08:15 Premiere Date 08/28/18

Can You Take Expired Drugs?
S5 E30 Length 03:25 Premiere Date 08/21/18

Can You Take Expired Drugs?
S5 E30 Length 03:20 Premiere Date 08/21/18

Will This Pop a Balloon?
S5 E29 Length 08:11 Premiere Date 08/07/18

Will This Pop a Balloon?
S5 E29 Length 07:52 Premiere Date 08/07/18

Yellowstone and Their Steaming Acid Pools of Death
S5 E28 Length 02:59 Premiere Date 08/01/18

How Air Conditioning Works
S5 E27 Length 04:23 Premiere Date 07/23/18

How Air Conditioning Works
S5 E27 Length 04:35 Premiere Date 07/24/18

3 Most Useful Kitchen Gadgets - Are They Worth It?
S5 E26 Length 03:12 Premiere Date 06/17/18

Why Does Stinky Cheese Stink?
S5 E25 Length 04:57 Premiere Date 07/10/18

Why Does Stinky Cheese Stink?
S5 E25 Length 08:15 Premiere Date 07/10/18

Hydrangeas and the Science of Do-Overs
S5 E24 Length 04:10 Premiere Date 07/03/18

Hydrangeas and the Science of Do-Overs
S5 E24 Length 08:15 Premiere Date 07/03/18

Surströmming: The Secrets of this Stinky Swedish Fish
S5 E23 Length 07:54 Premiere Date 06/26/18

Surströmming: The Secrets of this Stinky Swedish Fish
S5 E23 Length 08:15 Premiere Date 06/26/18

How Do Hydrangeas Change Colors?
S5 E22 Length 05:05 Premiere Date 06/19/18

How Do Hydrangeas Change Colors?
S5 E22 Length 05:39 Premiere Date 06/19/18

Are We Breathing Caesar's Last Breath
S5 E21 Length 05:24 Premiere Date 06/12/18

Are We Breathing Caesar's Last Breath
S5 E21 Length 05:46 Premiere Date 06/12/18

How Seashells Are Made
S5 E20 Length 03:43 Premiere Date 06/05/18

How Seashells Are Made
S5 E20 Length 04:16 Premiere Date 06/05/18

The Ultimate Donut Battle: Cake vs. Yeast
S5 E19 Length 04:32 Premiere Date 05/29/18

The Ultimate Donut Battle: Cake vs. Yeast
S5 E19 Length 04:41 Premiere Date 05/29/18

Chameleons Are Masters of Nanotechnology
S5 E18 Length 03:48 Premiere Date 05/22/18

Chameleons Are Masters of Nanotechnology
S5 E18 Length 04:14 Premiere Date 05/22/18

How Milk Becomes Cheese
S5 E17 Length 06:44 Premiere Date 09/10/18

Does Melatonin Do Anything?
S5 E16 Length 04:22 Premiere Date 05/01/18

How Do Airbags Work?
S5 E15 Length 03:11 Premiere Date 05/01/18

Burning Ice from the Ocean Floor
S5 E14 Length 03:44 Premiere Date 09/10/18

Small Bottle, HUGE Fireball (How Flame Jetting Works)
S5 E13 Length 04:09 Premiere Date 04/17/18

Why Can’t You Buy Fresh Olives?
S5 E12 Length 03:15 Premiere Date 04/10/18

What's That After-Rain Smell Made Of?
S5 E11 Length 03:58 Premiere Date 09/10/18

The Half-Life of Uranium & Collecting Gold in Acid
S5 E10 Length 02:51 Premiere Date 09/10/18

How Do We Know the Half Life of Uranium?
S5 E10 Length 05:39 Premiere Date 03/27/18

Cow Burps Are Warming the Planet
S5 E9 Length 02:49 Premiere Date 09/10/18

Cow Burps Are Warming the Planet
S5 E9 Length 05:39 Premiere Date 03/20/18

What Are Century Eggs?
S5 E8 Length 02:52 Premiere Date 03/13/18

What Are Century Eggs?
S5 E8 Length 05:39 Premiere Date 03/13/18

TV Forensics: What Do CSIs Actually Do?
S5 E7 Length 04:16 Premiere Date 09/10/18

TV Forensics: What Do CSIs Actually Do?
S5 E7 Length 05:39 Premiere Date 03/06/18

Nose Blindness, Mouthwash, and Hand Sanitizer--Your Question
S5 E6 Length 02:24 Premiere Date 09/10/18

How to Make the Best Cheap Hot Cocoa Possible
S5 E5 Length 03:04 Premiere Date 02/20/18

How to Make the Best Cheap Hot Cocoa Possible
S5 E5 Length 05:39 Premiere Date 02/20/18

Chemtrails
S5 E4 Length 02:29 Premiere Date 02/06/18

Chemtrails
S5 E4 Length 05:39 Premiere Date 02/06/18

The Race to Invent the Periodic Table
S5 E3 Length 05:34 Premiere Date 01/30/18

Do Ketogenic Diets Really Work?
S5 E2 Length 05:39 Premiere Date 01/23/18

The Only Video You'll Ever Need to Watch About Gluten
S5 E1 Length 05:39 Premiere Date 01/16/18

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