Daily Online News

For example, the oxygen molecule consists of two atoms of oxygen. In the case of oxygen, the bond that holds the two atoms together is known as a covalent bond, and here is how it works. The oxygen atom has 8 each of protons, neutrons, and electrons. The protons and neutrons are found in the center of the atom, known as the nucleus, and the electrons surround the nucleus in layers, or shells. The oxygen atom has 2 electrons in its first shell, and 6 in its second and outer shell. However, in chemistry, there exists the octet rule, which states that atoms generally strive to have 8 electrons in their outer shell. The oxygen therefore is 2 electrons away from a complete outer shell. When it binds with another oxygen atom, they can share two pairs of electrons and so each will have 8. When atoms share electrons like that, they form a molecule through a covalent bond. Molecules Formed by Ionic Bonds Molecules can also be formed through other kinds of chemical bonds, for ...

December 17 th is Willard Libby's birthday. Libby was the American physical chemist who developed the carbon-14 dating technique. This method is used to determine the age of 'once living' objects up to approximately 50,000 years. Carbon 14 is an isotope of carbon that is created naturally in the atmosphere by cosmic rays which in turn is breathed by living things or absorbed by plants. Over a lifetime of breathing, plants and animals maintain a natural ratio of carbon-14 to carbon-12. When the living thing dies, it stops absorbing the carbon-14 from the air.                                                               14 7 N + 1 0 n → 14 6 C + 1 1 H Carbon-14 decays into nit...

Researchers are developing a new kind of geothermal power plant that will lock away unwanted carbon dioxide (CO 2 ) underground -- and use it as a tool to boost electric power generation by at least 10 times compared to existing geothermal energy approaches. The technology to implement this design already exists in different industries, so the researchers are optimistic that their new approach could expand the use of geothermal energy in the U.S. far beyond the handful of states that can take advantage of it now. At the American Geophysical Union meeting on Friday, Dec. 13, the research team debuted an expanded version of the design, along with a computer animated movie that merges advances in science with design and cognitive learning techniques to explain the role that energy technologies can have in addressing Climate -Change'> climate change. The new power plant design resembles a cross between a typical geothermal power plant and the Large Hadron Col...

Unless nitrogen emissions are curbed, the diversity of plant communities in Europe's forests will decrease. Atmospheric nitrogen deposition has already changed the number and richness of forest floor vegetation species in European forests over the last 20-30 years. In particular, the coverage of plant species adapted to nutrient-poor conditions has reduced. However, levels of nitrogen deposition in Finnish forests remain small compared to Southern and Central Europe. These results will be presented as part of international research published in the journal Global Change Biology . Researchers from the Finnish Environment Institute and the Finnish Forest Research Institute (Metla) participated in this research, which concludes that unless nitrogen emissions are curbed, the diversity of plant communities in Europe's forests will decrease. The work involved the examination of long-term changes in vascular plant communities within a 1 300 monitoring grid coveri...

The U.S. Food and Drug Administration today issued a proposed rule to require manufacturers of antibacterial hand soaps and body washes to demonstrate that their products are safe for long-term daily use and more effective than plain soap and water in preventing illness and the spread of certain infections. Under the proposal, if companies do not demonstrate such safety and effectiveness, these products would need to be reformulated or relabeled to remain on the market. Today’s action is part of a larger, ongoing review of antibacterial active ingredients by the FDA to ensure these ingredients are proven to be safe and effective. This proposed rule does not affect hand sanitizers, wipes, or antibacterial products used in health care settings. Millions of Americans use antibacterial hand soap and body wash products. Although consumers generally view these products as effective tools to help prevent the spread of germs, there is currently no evidence that they are an...

যুদ্ধাপরাধের দণ্ড কার্যকর শুরুর পর প্রথম বিজয় দিবসে স্মৃতিসৌধে এসে ‘দেশজুড়ে নাশকতা ঘটিয়ে চলা জামায়াত-শিবির’ প্রতিরোধের শপথ নিতে বললেন মুক্তিযোদ্ধারা। সাত বছরের নাতীকে সঙ্গে নিয়ে সোমবার সকালে সাভারে জাতীয় স্মৃতিসৌধে এসেছিলেন পাথালিয়ার মুক্তিযোদ্ধা মো. দবির উদ্দীন। একাত্তরে দেশরক্ষার শপথ নিয়ে যুদ্ধে ঝাঁপিয়ে পড়ার সেই দিনগুলোর স্মৃতি স্মরণ করে তিনি বলেন, “এবারের বিজয় দিবসে আমাদের শপথ জামায়াত-শিবিরের সহিংসতার বিরুদ্ধে দেশবাসীকে এক করে প্রতিবাদ করা। তাদের রাষ্ট্রবিরোধী কাজের বিরুদ্ধে প্রতিরোধ গড়ে তোলা।” মুক্তিযোদ্ধা ইসমত কাদির গামা বলেন, স্বাধীনতার এতো ...

বেয়াল্লিশ বছর আগে যে মুহূর্তে যে স্থানটিতে বাঙালির মুক্তির সনদ লেখা হয়েছিল, মুক্তিযুদ্ধে বিজয়ের সেই ক্ষণে সেই স্বাধীনতার উদ্যানেই লাখো কণ্ঠ গাইল ‘আমার সোনার বাংলা, আমি তোমায় ভালোবাসি’। রবীন্দ্রনাথ ঠাকুরের এই গানটিই একাত্তরের রণাঙ্গনে বাঙালি জাতিকে প্রেরণা যুগিয়েছিল, যা পরে বাংলাদেশের জাতীয় সংগীত হিসাবে গ্রহণ করা হয়। সোহরাওয়ার্দী উদ্যানে স্থাপিত ‘বিজয় ২০১৩’র মঞ্চে সোমবার বিকাল ৪টা ৩১মিনিটে এই গানে কণ্ঠ মেলান উপস্থিত জনতা। এবার সম্মিলিতভাবে এই উত্সব পালন করছে বিজয় ২০১৩ উদযাপন জাতীয় কমিটি, গণজাগরণ মঞ্চ, সেক্টর কমান্ডার্স ফোরাম, মুক্তিযুদ্ধ চেতনা বাস্তবায়ন কমিটি এবং বিজয় ৪:৩১ মঞ্চ। জাতীয় সংগীত পরিবেশনের আগে স্বাধীন বাংলা বেতার কেন্দ্রের শিল্পীরা পরিবেশন করেন একাত্তরে মুক্তিকামী মানুষকে শক্তি যোগানো বিভিন্ন গান। পরে তারাও সমবেত কণ্ঠের জাতীয় সংগীতে অংশ নেন। ১৯৭১ সালের ১৬ ডিসেম্বর বিকাল ৪টা ৩১ মিনিটে পাকিস্তানি বাহিনী এই উদ্যানেই আত্মসমর্পণের দলিলে সই করেছিল, তখন এর নাম ছিল রেসকোর্স ময়দান।মুক্তিযুদ্ধের উপ অধিনায়ক অবসরপ্রাপ্ত এয়ার ভাইস মার্শাল একে খন্দকার বীর উত্তম বলেন, “সেই ক্ষণ...

Bangladesh attempts to create the world's largest 'human flag' It is a unique way of celebrating victory and freedom that befits the passions behind the 1971 Liberation War. 1   0   26   ...

December 16 th is Johann Wilhelm Ritter's birthday. Ritter was a German scientist who invented one of the first dry pile galvanic batteries. Early batteries used electrodes dipped in an acid solution where the energy is produced through oxidation reactions. A dry pile uses just enough moisture to function and did not have the dangers of spilling acid solutions. Ritter's pile used alternating pieces of silver and zinc foil separated by pieces of paper. Ritter was also responsible for the discovery of the ultraviolet region of the electromagnetic spectrum. While investigating the discoloration of silver salt crystals exposed to sunlight, he discovered there was a part of sunlight beyond the violet range responsible for the discoloration. He initially called this part of the light spectrum 'de-oxidizing rays' because of their chemical reactivity. Find out more about electrochemical cells , redox reactions and what else occurred on this day in science histor...

What Is Chemistry? Chemistry is the study of matter and energy and the interactions between them. This is also the definition for physics, by the way. Chemistry and physics are specializations of physical science . Chemistry tends to focus on the properties of substances and the interactions between different types of matter, particularly reactions that involve electrons. Physics tends to focus more on the nuclear part of the atom, as well as the subatomic realm. Really, they are two sides of the same coin. Why Study Chemistry ? Because understanding chemistry helps you to understand the world around you. Cooking is chemistry. Everything you can touch or taste or smell is a chemical. When you study chemistry, you come to understand a bit about how things work. Chemistry isn't secret knowledge, useless to anyone but a scientist. It's the explanation for everyday things, like why laundry detergent works better in hot water or how baking soda works or why not all ...