Agriculture
Treating peanut allergy bit by bit
Hungry bug seeks hot meal
Growing Healthier Tomato Plants
Amphibians
Salamanders and Newts
Newts
Frogs and Toads
Animals
Young Ants in the Kitchen
Firefly Delight
Polar Bears in Trouble
Behavior
Brain cells take a break
Ear pain, weight gain
The chemistry of sleeplessness
Birds
Pigeons
Vultures
Flamingos
Chemistry and Materials
Spinning Clay into Cotton
Flytrap Machine
Music of the Future
Computers
Graphene's superstrength
The Shape of the Internet
Music of the Future
Dinosaurs and Fossils
Dino Bite Leaves a Tooth
Teeny Skull Reveals Ancient Ancestor
Fingerprinting Fossils
E Learning Jamaica
2014 GSAT Results for Jamaican Kids
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
Results of GSAT are in schools this week
Earth
Undersea Vent System Active for Ages
Arctic Algae Show Climate Change
What is groundwater
Environment
When Fungi and Algae Marry
Pumping Up Poison Ivy
Fungus Hunt
Finding the Past
Ancient Cave Behavior
Fakes in the museum
Watching deep-space fireworks
Fish
Pygmy Sharks
Dogfish
Saltwater Fish
Food and Nutrition
Yummy bugs
Allergies: From Bee Stings to Peanuts
Strong Bones for Life
GSAT English Rules
Adjectives and Adverbs
Who vs. Whom
Pronouns
GSAT Exam Preparation Jamaica
How are students placed after passing the GSAT exam
Results of GSAT are in schools this week
The Annual GSAT Scholarships
GSAT Exams Jamaica Scholarships
Results of GSAT are in schools this week
Access denied - Disabled boy aces GSAT
2014 GSAT Results for Jamaican Kids
GSAT Mathematics
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
Math Naturals
10 Common Mistakes When Preparing for the GSAT Math Test
Human Body
Football Scrapes and Nasty Infections
Workouts: Does Stretching Help?
Tapeworms and Drug Delivery
Invertebrates
Grasshoppers
Insects
Shrimps
Mammals
Badgers
Asian Elephants
Yorkshire Terriers
Parents
Raise a Lifelong Reader by Reading Aloud
How children learn
Children and Media
Physics
Invisibility Ring
The Pressure of Scuba Diving
Dreams of Floating in Space
Plants
Stalking Plants by Scent
Hungry bug seeks hot meal
Fungus Hunt
Reptiles
Box Turtles
Crocodilians
Crocodiles
Space and Astronomy
Unveiling Titan
A Moon's Icy Spray
Mercury's magnetic twisters
Technology and Engineering
Reach for the Sky
Machine Copy
Weaving with Light
The Parts of Speech
Problems with Prepositions
Adjectives and Adverbs
What is a Noun
Transportation
Ready, unplug, drive
Where rivers run uphill
Revving Up Green Machines
Weather
Earth's Poles in Peril
Science loses out when ice caps melt
Watering the Air
Add your Article

Cold, colder and coldest ice

Most people know what happens at 0º Celsius (or 32 º Fahrenheit): Water freezes. When the temperature outside is below freezing, for example, a rain storm may become a blizzard of snow. A glass of water left in the freezer eventually becomes a glass of ice. The freezing point of water may seem like a simple fact, but the story of how water freezes is a little more complicated. In water at the freezing temperature, ice crystals usually form around a dust particle in the water. Without dust particles, the temperature can get even lower before the water turns to ice. In the laboratory, for example, researchers have shown that it’s possible to cool water down to -40º C — without producing a single ice cube. This “supercooled” water has many uses, such as playing an important part in helping frogs and fish survive low temperatures.In a more recent study, scientists showed how the temperature at which water freezes can be changed using electric charges. In this experiment, water exposed to a positive charge froze at higher temperatures than water exposed to a negative charge. “We are very, very surprised by this result,” Igor Lubomirsky told Science News. Lubomirsky, who worked on the experiment, works at the Weizmann Institute of Science in Rehovot, Israel.Charge depends on tiny particles called electrons and protons. These particles, together with particles called neutrons, make up atoms, which are the building blocks of all matter. An electron is a negative charge and a proton is a positive charge. In atoms with the same number of protons as electrons, the positive and negative charges cancel each other out and make the atom act like it has no charge. Water already has its own kind of charge. A water molecule is made of one oxygen atom and two hydrogen atoms, and when these atoms get together they make a shape like Mickey Mouse’s head, with the two hydrogen atoms being the ears. The atoms bond together by sharing their electrons. But the oxygen atom tends to hog the electrons, pulling them more toward itself. As a result, the side with the oxygen atom has a bit more negative charge. On the side with two hydrogen atoms, the protons aren’t balanced out as well by electrons, so that side has a bit of positive charge. Because of this imbalance, scientists have long suspected that forces due to electric charges could change the freezing point of water. But this idea has been hard to test and harder to verify. Earlier experiments looked at water freezing on metal, which is a good material to use because it holds electric charges, but water can freeze on metal with or without a charge. Lubomirsky and his colleagues got around this problem by separating the water and the charged metal with a special type of crystal that could generate electric fields when heated or cooled. In the experiment, the scientists placed four crystal discs inside four copper cylinders, then lowered the temperature of the room. As the temperature dropped, water droplets formed on the crystals. One disc was designed to give the water a positive charge; one a negative charge; and two gave no charge at all to the water. The water droplets on the crystal with no electric charge froze at -12.5º C on average. Those on a crystal with a positive charge froze at a higher temperature of -7º C. And on the crystal with a negative charge, the water froze at -18º C — the coldest of all. Lubomirsky told Science News he was “delighted” with his experiment, but the hard work is only beginning. They’ve taken the first step — observation — but now they have to explore the deep science of what is causing what they observed. These scientists have managed to show that electric charges affect the freezing temperature of water. But they don’t yet know why. POWER WORDS electron A stable, negatively charged subatomic particle. proton A stable, positively charged subatomic particle electric charge The property of matter responsible for all electric phenomena, in particular for the force of the electromagnetic interaction, occurring in two forms arbitrarily designated negative and positive. electric field A region of space characterized by the existence of a force generated by electric charge.

Cold, colder and coldest ice
Cold, colder and coldest ice








Designed and Powered by HBJamaica.com™