Tasting Through Your Nose - Experiment #102

"The smell of a food is as important as its taste! In fact, its smell actually influences how it tastes! If you doubt it, try this experiment.

You will need: 
Small peeled potato
2 spoons
Small grated apple
Grater


What to do: Grate part of a peeled potato and put it on a spoon. Grate an equal amount of a peeled apple and put it on a second spoon. Close your eyes and mix up the spoons so that you're not sure which is which. Hold your nose and taste each of the foods.

 

 

Why: The nose shares the airway (the pharynx) with the mouth. Therefore, we smell and taste food at the same time. Only salty, sweet, bitter and sour are pure tastes. Other "tastes" are combinations of taste and odor. Without the help of your nose, you may not be able to tell what you are eating."

What happened when CKS tried it: The potato tasted like both, but the apple tasted crunchy and sweet. I tried tasting chunks of potato and apple too. I guessed everything right - I knew which one was potato and which one was apple. They looked different so use a blindfold too. I guess I'm a good taster!

CKS rating: 4 stars - so fun you should try it a hundred times!

Banana Split - Experiment #329

"Can you place a banana in a bottle without using your hands? Amaze your friends with this party-trick science experiment. Watch carefully, because the banana is quicker than the eye in this split-second surprise. Moreover, it all has to do with molecules and air. Careful - boiling water involved! Also, it is best to do this in the sink.

You will need:
1/2 banana, peeled
teakettle with boiling water
clean, long, narrow bottle with banana-size mouth
funnel
dish towel

What to do: Put the funnel into the bottle neck and carefully fill the bottle almost to the top with boiling water (adult help recommended). Remove the funnel. Wrap a dish towel around the bottle and gently swirl the water around; then pour it out. Quickly, fit the pointed end of the half-banana downwards into the bottle neck so that it makes an airtight plug. (Watch the variables - the size of the banana and bottle neck, the amount of hot water, the time it takes - and be patient! You may have to do this experiment several times to get it right, but you will succeed!)

What happens: The banana is sucked down into the bottom of the bottle.

Why: The heat from the boiling water causes the air inside the bottle to expand, forcing some of it out. When the banana is placed into the mouth of the bottle and the cooling air inside the bottle shrinks again, the air pressure inside is reduced and the greater air pressure outside shoves the banana ahead of it into the bottle. This gives you an idea of what happens when air is removed from a space and nothing takes its place (partial vacuum). Just small differences in air pressure can cause things to move.

What now: You want to recycle the bottle, but the banana is inside it! WHAT CAN YOU DO? Just wait a few days. Let the bacteria in the banana do their chemistry work. Bacteria give off enzymes that break down proteins and starches. The banana will eventually change chemically (ferment) and soften enough to be removed easily." If a monkey tries this, he would want to get it out immediately to eat it!

What happened when CKS tried it?: It worked on the first try! The banana was going so slow, you had to squint a little to see it moving into the bottle. And wait a sec....when it gets in the bottle, it goes 'BOMP'! It sucks in really fast and scares you a little.

CKS rating: 4 stars - Like 3 ice cream cones!

Invisible Ink - Experiment #28

"You can use a lemon to write a secret message.

You will need:
1/2 lemon
saucer
water
cotton swab (Q-tip)
white paper
lamp

What to do: Squeeze the lemon juice into the saucer. Add a few drops of water and mix well with a spoon. Dip the swab into the lemon juice. Then use the swab to write a message on ordinary white paper. When it dries, the writing will be invisible. When you want to read the message, heat the paper by holding it near a light bulb.

What happens: The words appear on the page.

Why: The juice of lemons and other fruits contain compounds of carbon. These compounds are nearly colorless when you dissolve them in water. But, when you heat them, the carbon compounds break down and produce carbon, which is black."


What happened when CKS tried it? My message didn't show up that much - it was clear and shiny and I could hardly see the letters. My mom used a lot of lime juice and it showed up well and it was a little yellow, but some other letters were clear. My advice when you try this is: Use a lot of lemon juice or lime juice to make this work.

CKS rating: 4 stars - Pretty fun!