This common antioxidant actively slows the signs of ageing in human skin. A common antioxidant used as a dye in laboratories could one day be added to skin care products as way to slow the signs of ageing, a recent study on the effects of a chemical called methylene blue on human skin cells suggests. The compound did a better job of helping cells called fibroblasts survive longer, divide faster, and show fewer indicators of ageing than several other antioxidants.
"I was encouraged and excited to see skin fibroblasts, derived from individuals more than 80 years old, grow much better in methylene blue-containing medium with reduced cellular senescence markers," said lead researcher Zheng-Mei Xiong from the University of Maryland. 'Cellular senescence' is the term used to describe when normal cells stop dividing. Fibroblasts are part of a family of connective tissues responsible for producing materials such as cartilage or bone. As we age, fibroblasts produce lower amounts of collagen and higher amounts of an enzyme that breaks it apart. The Science of Sunscreen & How it Protects Your Skin. Click to enlarge With summer more or less here (stifle those sniggers, English readers), it seemed as good a time as any to examine the chemicals in sunscreen. It’s a product that many of us may take for granted, but you’ve got chemistry to thank for it preventing your skin turning lobster red in the summer sun.
There are a number of chemical molecules used in currently available sunscreens, with the exact formulation actually depending on where in the world you live. Additionally, the chemistry of these molecules can help explain why sunscreen has to be reapplied periodically. To understand the protection that sunscreen affords, we first have to understand what we’re trying to protect ourselves from. UVB (wavelength ~290-320nm) is responsible for around 5% of the UV radiation reaching Earth, with the majority of it also being absorbed by the atmosphere. So, how does sunscreen work chemically? These organic chemicals also explain, to an extent, why sunscreen has to be reapplied. Revision Quizzes for your PC, Tablet or Smartphone. 50 Awesome Chemistry Videos For The Busy Science Teacher.
Though we don’t often recognize it, chemistry defines nearly every element of our everyday lives. From the reactions that fuel the sun to the biology of our bodies to the technology in our gadgets, chemistry is at the heart of everything we do and is the central science that unites biology, physics, geology, astronomy, medicine, and countless other fields. Yet chemistry doesn’t always get the credit and recognition it deserves for playing such an awesome role in, well, everything. If you’ve been slighting chemistry, there’s no better time to give the field the credit it deserves than National Chemistry Week. Founded in 1987, the week-long event has helped bring awareness to the role chemistry plays both in our lives today and in our future. You can get in the spirit of the event by checking out a few (or all) of these amazing chemistry videos online.
Some are funny, some impressive, but all will showcase the true awesomeness of chemistry. Amazing Reactions and Experiments Lectures Courses. Chemstuff | Mr Banks's Chemistry Site. Four new element names are on the table | Science | AAAS. Time to throw out that old copy of the periodic table: New names have just been penciled in for four elements officially recognized back in December. Nihonium, moscovium, tennessine, and oganesson will grace the blocks assigned to atomic numbers 113, 115, 117, and 118, said the International Union of Pure and Applied Chemistry (IUPAC) today.
Barring any serious challenges during a 5-month public comment period that ends in November, the new names will be officially added to the table (above). Nihonium, discovered by a Japanese team, means “the land of the rising sun,” while moscovium and tennessine are named after places near the labs where they were discovered (Moscow and Tennessee, of course). And oganesson recognizes the work of Russian chemist Yuri Oganessian. By tradition, the right to suggest a name for an element is granted to its discoverer, although IUPAC has the final say.
And with different labs often racing to be first, it’s not always clear who should have the honor. Theconversation. When we say “salt”, we usually mean the stuff we sprinkle on our chips, which is sodium chloride (NaCl). But, technically speaking, this is just one example of a salt. Molecules that have an electrical charge are called ions. Those with a positive charge are cations, and those with a negative charge are anions. They’re like the opposite ends of a magnet, so anions attract cations. Acids are substances release positively charged hydrogen ions (H+) when in water, while bases release negatively charged hydroxide ions (OH-) in water. When mixed together, they neutralise each other and produce a salt. So salts are just made up of positively charged cations bound with negatively charged anions. Salty Not all salts are safe to eat, and not all of them taste salty. While adding salts to water is a pretty safe chemical reaction, in their elemental state, each component can be highly reactive.
Adding salt makes food last longer by reducing the “water activity” of foods. Defensive eating. The Periodic Table of Videos - University of Nottingham. The Periodic Table of Elements. Path to the Periodic Table. Lesson Overview This activity allows students to re-create the thought process that Dmitri Mendeleev and Julius Lothar Meyer went through to devise their early periodic tables.
The students are given cards (provided at the end of the teacher activity page), each with the name of an element, its symbol, and some properties. The students are then asked to sort the elements into a table of some sort, in any way that makes sense to them. In arriving at arrangements similar to those devised independently by Mendeleev and Meyer, they will come to a greater understanding and appreciation of how the periodic table is organized and of the information it contains. The activity is carried out in three steps. Student Ability Level and Grouping This activity is appropriate for high school introductory chemistry students or ninth-grade physical science students. Expected Student Background and Skills Students should have an understanding of elements and compounds, as well as of atoms and molecules.
JINA-CEE Educational Gallery: Interactive Movies/Games on Nucleosynthesis in Nuclear Astrophysics. Chem year nine. SchoolMedia Interactive - Changes in the Properties of Matter - Physical and Chemical. Chemical Mixup | MINT Center - The University of Alabama. Mixtures, elements and compounds. KS3 CHEMISTRY Science Quizzes revision notes Practice Questions multiple choice quiz worksheets crossword puzzles exercises.
Doc B's revising for KS3 SCIENCE Doc Brown's Chemistry KS3 chemistry revision notes and practice questions KS3 CHEMISTRY and Earth Science multiple choice revision QUIZZES I appreciate SAT levels have gone, but I hope these KS3 chemistry Quizzes will still be of some use. SEE ALSO the KS3 Science Quiz compilations 20 Question multiple choice QUIZ on ORGANISMS, BEHAVIOUR and HEALTH 20 Question multiple choice QUIZ on CHEMICAL and MATERIAL BEHAVIOUR 20 Question multiple choice QUIZ on ENERGY, ELECTRICITY and FORCES 20 Question multiple choice QUIZ on THE ENVIRONMENT, EARTH and UNIVERSE KS3 Chemistry and Earth Science Multiple Choice Questions The KS3 Chemistry Questions are selected at random from big databases.
PLEASE NOTE: (1) <= back on the link bar returns you to the previous web page. (2) Don't use the usual refresh button on the upper browser to repeat the quiz, use the REPEAT QUIZ - fresh Q's on the quiz link bar. Multiple choice quizzes for KS3 CHEMISTRY & Earth Science version on pH and. Chemistry resources - Listing page. Mahjong Chem -- Free Game to Practice Chemistry Knowledge! Also available for your iPhone/iPad/iPod here or Android device here. Brought to you by the Chemistry Department at Stetson University. The entire content of this web site is copyrighted by Stetson University under the copyright laws of the United States (Title 17, U.S. Code). You are welcome to repost for educational purposes.