- Make pH Paper Test Strips
You can use red cabbage pH indicator to make your own pH paper test strips. It's simple to do and makes it much easier to test the pH of liquids since you just have to apply a drop to the strip to see the color change. I have a tutorial for making pH paper test strips, but here are quick instructions for how I made the strips featured in the photo:
- Tear a red cabbage leaf into pieces and put the pieces into a microwave-safe bowl.
- Microwave the leaves 2-3 minutes or until they are cooked and soft. Allow the cabbage to cool.
- Cut a coffee filter into test strips. The size and shape of the pH test strips isn't critical.
- Press a cooked cabbage piece onto a test strip to saturate it with color.
- You can use a toothpick to apply a drop of a chemical you want to test onto a damp test strip or you can allow the pH test strips to dry for use at a later time. The test strips will work equally well damp or dry.
- If you are keeping the test strips for later, store them in a cool, dry location and keep them out of direct sunlight. A cardboard box or paper bag would work well.
Make Cabbage pH Paper Test Strips | Make Poinsettia pH Paper Test StripsMake pH Paper Test Strips originally appeared on About.com Chemistry on Wednesday, February 8th, 2012 at 07:21:52.
- Tear a red cabbage leaf into pieces and put the pieces into a microwave-safe bowl.
- This Day in Science History - February 8 - Dmitri Mendeleev
February 8th is Dmitri Mendeleev's birthday. Most people associate Mendeleev the first accepted periodic table of the elements. His table ordered the elements by increasing atomic weight where columns of elements had similar chemical properties and is the immediate forerunner of the modern periodic table.
Mendeleev was also the man responsible for making Russia "metric". As Director of Russia's Bureau of Weights and Measures, he was instrumental in bringing the metric system to Russia.
In his personal life, he was famous for his "grooming". Mendeleev was widely known for his long hair and wild beard. He would only cut his hair or trim his beard once a year. He had one minor scandal where he was labeled a bigamist for a legal technicality for not waiting the required seven years after a divorce before marrying his second wife.
Find more about Mendeleev and what else occurred on this day in science history.This Day in Science History - February 8 - Dmitri Mendeleev originally appeared on About.com Chemistry on Tuesday, February 7th, 2012 at 22:05:51.
- Glow in the Dark Slime Instructions
When I write up a project, there are two sets of instructions. There are the cover-all-the-bases instructions. where I tell you all the different ways to make something. Then there are the instructions I actually use for myself when I test a project. When I made the glow-in-the-dark slime you see in the picture, here is what I actually did:
Materials- borax (from laundry aisle of a grocery store)
- Elmer's™ non-toxic blue glue gel (sold with office or school supplies)
- Glow-Away™ washable paint (sold near tempera paint at Michael's craft store)
- water
- bowls or cups
- spoons
- measuring cups
- In one bowl, mix 1/3 cup glue with 1 cup water. I used a whisk, since stirring with a spoon was slow.
- Stir or whisk in about half a tube of the paint.
- Pour about half a cup of hot water into a cup or second bowl.
- Stir in borax until it stops dissolving (starts to leave some at the bottom). This makes a saturated solution without any measuring at all.
- Measure and mix 1/3 cup of the borax solution (the clear part, not the undissolved stuff at the bottom) with 1 cup of the glue/glow mixture.
- You can try to whisk this, but it's easier to use your hands.
- Activate the glow by holding the slime under a bright light. Any light works, but the brightest glow will come from a UV lamp (black light) or a fluorescent bulb. Turn out the lights!
- Wash your hands when you are done playing with your slime.
- You can store the slime indefinitely in a sealed baggie.
Photo: Ryan with glowing slime. (Anne Helmenstine)Glow in the Dark Slime Instructions originally appeared on About.com Chemistry on Tuesday, February 7th, 2012 at 07:02:33.
- What Do Whales Drink?
Have you ever wondered what whales drink?
You probably know all animals require water to live. Humans drink fresh water and get water from the foods we eat. If we eat foods that contain enough water, we could get the water we need without actually drinking it. If we drink seawater the salt overwhelms our kidneys, essentially making us thirstier. However, whales ingest some seawater with the foods they eat, yet are fine. Just like us, whales need fresh water in order to live. They get most of this water from the food they eat (krill, fish, or plankton). Whale kidneys are made to extract water from their food and possibly some seawater. This is similar to the way terrestrial desert animals get water from their food.
Water Intoxication | Sports Drinks Versus WaterWhat Do Whales Drink? originally appeared on About.com Chemistry on Monday, February 6th, 2012 at 22:59:42.
- This Day in Science History - February 7 - Periodic Table and Law of Octaves
February 7, 1863 was the day John Newlands published what would be known as "The Law of Octaves". Newlands discovered if he ordered the known elements by increasing atomic weights, the chemical properties of the elements would be similar for every eighth group. Since the pattern seemed to follow the same pattern as the piano's octaves, he called his periodic law the "Law of Octaves"
The reception Newlands received after publishing this discovery was primarily severe criticism. His ideas were publicly labeled 'useless' and 'arbitrary' and caused him to give up his work on organizing the elements. In the next decade, two other chemists published periodic laws based on atomic weights. Mendeleev and Meyer both independently identified their versions of the Law of Octaves and showed Newlands' ideas were neither 'arbitrary' no 'useless'. The periodic table would follow the increasing atomic weights until the discovery of atomic numbers by Henry Moseley in 1914 and the current periodic table was born.
Find out what else occurred on this day in science history.This Day in Science History - February 7 - Periodic Table and Law of Octaves originally appeared on About.com Chemistry on Monday, February 6th, 2012 at 22:05:02.
- Matryoshka Molecules
Matryoshka Molecules A bronze matryoshka doll - The metal in the metal in the metal: New way to highly efficient catalysts and nanotubes with unusual symmetry.
Image: Just like in the Russian wooden toy, a hull of 12 copper atoms encases a single tin atom.
This hull is, in turn, enveloped by 20 further tin atoms.
With their large surfaces these structures can serve as highly efficient catalysts.
[Credit: TUM]
- Macroporous Polystyrene
Macroporous Polystyrene All foamed up: synthesis of macroporous polystyrene through polymerization of foamed emulsions.
Image: An ideal template for the production of macroporous polystyrene can be prepared from foamed oil-in-water emulsions containing styrene, water, glycerol, and sodium dodecylsulfate. After addition of a photoinitiator the mixture is polymerized with UV light and the foam structure of the precursor is transferred to the polymer. The resulting materials display densely packed cells with windows between adjacent pores (SEM image; scale bar: 250 ?m).
[Credit: Angewandte Chemie]
- Luminescent Nanocrystals
Luminescent Nanocrystals Bright lights of purity: Berkeley Lab researchers discover why pure quantum dots and nanorods shine brighter.
Image: Ion exchange of semiconductor nanocrystals yielded materials with poor optoelectronic properties such as low photoluminescence quantum yields. The reason for the low quantum yields of these nanocrystals are impurities at the level of a few atoms per nanocrystal ...
[Credit: Berkeley Lab]
- Toxic Amino Acids
Toxic Amino Acids Deadly chinese mushrooms: Amino acids revealed as cause of deaths in Yunnan province.
Image: Two unusual and toxic amino acids, 2R-amino-4S-hydroxy-5-hexynoic acid and 2R-amino-5-hexynoic acid have been isolated from the fruiting bodies of the mushroom Trogia venenata.
[Credit: Angewandte Chemie]
- Oxygen as Insulator, Semiconductor and Metal
Oxygen as Insulator, Semiconductor and Metal Oxygen molecule survives to enormously high pressures - RUB researcher calculates stability thresholds and structures of solid oxygen.
Image - Structures of solid oxygen under high pressure:
At 1.9 TPa, oxygen polymerizes and assumes a square spiral-like structure, which is semi-conducting ,,,
[Figure: Jian Sun]
