Hot water freezes faster than cold - and now we know why.Hot water seems to freeze faster than cold water, known as the Mpemba effect. The effect was named after the Tanzanian student who in 1963 noticed that hot ice cream mix freezes faster than a cold one. The effect was first observed by Aristotle in the 4th century BC, then later Francis Bacon and René Descartes. Mpemba published a paper on his findings in 1969. Theories for the Mpemba effect have included: faster evaporation of hot water, therefore reducing the volume left to freeze; formation of a frost layer on cold water, insulating it; and different concentrations of solutes such as carbon dioxide, which is driven off when the water is heated.
Simulador enfoque camaras digitalesLighting Lighting is the single biggest determinant of how your camera needs to be set. With only a few exceptions, you can never have too much light. Use this slider to experiment with different indoor and outdoor lighting conditions. A-level ChemistryA-level Chemistry is a rigorous, challenging and ultimately rewarding course that develops students' scientific skills and knowledge. There are six units in the full A-level – three at AS and three at A2. Four of the units are assessed by exam. The remaining two units are internal assessments of investigative and practical skills.
Make Your Own Co2 Fire ExtinguiserMaterials: - Candle- Wire Coat Hanger- Two 1 liter plastic soda bottles- Matches- Baking soda- Vinegar- Pliers and Scissors- Adult Supervision Watch the Co2 Fire Extinguisher Video Process For Making Your Own Co2 Fire Extinguisher 1) Use the scissors to cut off the tops of the plastic bottles.ChemCollective: Virtual LabsThe Virtual Lab is an online simulation of a chemistry lab. It is designed to help students link chemical computations with authentic laboratory chemistry. The lab allows students to select from hundreds of standard reagents (aqueous) and manipulate them in a manner resembling a real lab. More information and offline downloads.
Simulador Ondas AguaLoading... Made by Evan Wallace This demo requires a decent graphics card and up-to-date drivers.Chemistry Virtual TextbookAcid-base chemistry can be extremely confusing, particularly when dealing with weak acids and bases. This set of lessons presents an updated view of the Brønsted-Lowry theory that makes it easy to understand answers to common questions: What's the fundamental difference between a strong acid and a weak acid? Can acid A neutralize base B?California Trees Nailed As The Source Of Mystery InfectionsThe Canary Island pine is one tree species that hosts a fungus that causes disease in humans. Shamanic Shift Center/UC Davis/Wikimedia hide caption itoggle caption Shamanic Shift Center/UC Davis/Wikimedia The Canary Island pine is one tree species that hosts a fungus that causes disease in humans.
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