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World's lightest solid

6/7/2019

Wetsuits
Firefighter suits
Skylights
Windows
Rockets
Paints
Cosmetics
Nuclear weapons

Because of aerogel's unique structure, its use as an insulator a no-brainer. The super-insulating air pockets with the aerogel's structure almost entirely counteract the three methods of heat transfer: convection, conduction and radiation [source: Cabot Corporation].

Even though aerogel is still quite expensive, the good news is that studies have shown that aerogel insulation used in wall framing and hard-to-insulate areas such as window flashing can save a homeowner up to $750 per year. In addition to helping homeowners save money, aerogel insulation can significantly reduce your carbon footprint. Companies are racing to find a way to bring costs down, but for now, aerogels are more affordable for NASA than the general public. Still, aerogels are put to use by construction companies, power plants and refineries. Perhaps when it's more affordable, aerogel will achieve that A-list status.”
https://science.howstuffworks.com/aerogel4.htm

“In general, gels are three-dimensional networks of solid, spanning the entire volume of a fluid medium. You're probably most familiar with hydrogels, where the fluid is water - think of Jell-O. Aerogels are composed of a solid network spanning a gaseous medium, instead of a liquid one. The substitution of gas for liquid means that the density of standard aerogel is the lowest of any known bulk solid.

The most common aerogels are made from silica, although metal oxides and organic materials have also been used. Silica aerogels have very, very low thermal and electrical conductivity, making them wonderful insulators. Metal oxide aerogels have similarly low density and high porosity, and are often used as chemical catalysts.

Aerogels are made by supercritically drying a liquid-phase gel, which ensures that the structure of the aerogel is maintained throughout the drying process. Supercritical drying avoids the liquid-gas phase transition by heating and pressurizing the material to above its critical point, whereupon it becomes a supercritical fluid.

The supercritical fluid has properties of both liquid and gas: very compressible, has no surface tension (due to lack of liquid-gas interface), diffuses through solids, and is still dense enough to support a solid structure. The supercritical fluid is then cooled and depressurized into the gas phase. If one were to evaporatively dry the liquid solvent - where the liquid is simply heated until it becomes a gas - the surface tension between the gas and the liquid would be too strong for the aerogel's delicate structure, and the gel would collapse. We built our own supercritical dryer for purposes of this project.”
https://web.mit.edu/3.042/team3_10/background.html

Here is a 12 minute segment that has an interesting examination of the properties of Aerogels.
Notice that they do not wear goggles during the experiment. They make that choice probably because they’re melting food. The narrator also tastes the food being melted – also not a good choice for a lab situation.
https://twistedsifter.com/videos/aerogels-are-the-worlds-lightest-solids/

This blog it about a topic that is more advanced than your typical Introductory Chemistry class. I include it for the teacher’s information and possible student reference.

Past blog posts about Final Exams and the End of the School Year include:

06/08/2014            Final Exams – End of Year Preparation
06/15/2014            End of Year Activity – Lab Clean-Up
06/29/2014            Summer Vacation
05/28/2015            Extra Credit II
06/11/2015            End of Year Reflection
06/04/2015            Final Exams II
06/19/2016            End of Year Reflection II

*This Blog contains several entries that would be helpful to your chemistry classroom. Check out the Topic List to help you to find past Blog entries.

Also, Write To Me about your successes, challenges, or questions in the Chemistry Classroom.

Remember, buying a copy of the lab book Chemistry on a Budget can be very useful to your Chemistry classroom with labs and class article ideas.

Have a great weekend!

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Definition of the kilogram just changed

5/31/2019

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earliest molecule in the universe

5/24/2019

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The book Chemistry on a Budget contains inexpensive chemistry labs that are useful with easy to obtain materials.

There are two versions of each lab, one with a ten-question conclusion and one with directions for a full lab report. This way the teacher has the option! Each lab is two pages to allow for one two-sided handout.

A 5-Star Customer Review of Chemistry on a Budget at amazon.com states:

“[S]traight forward, to the point, using household chemicals… this is the lab book for you.
I teach high school chemistry and this is exactly what I was looking for. Labs included simple household chemicals that could be easily found. Nice format, easy to follow along procedures, and touches on every topic of our chemistry curriculum.”

You can buy this lab book for $23 at amazon.com or lulu.com. It will take 1-2 weeks to get to you -- Order Now. It’s a great resource!

http://www.amazon.com/Chemistry-Budget-Marjorie-R-Heesemann/dp/0578129159/ref=sr_1_1?s=books&ie=UTF8&qid=1389410170&sr=1-1&keywords=chemistry+on+a+budget

http://www.lulu.com/shop/marjorie-r-heesemann/chemistry-on-a-budget/paperback/product-21217600.html

*Some of you have already purchased my lab book – be sure to check out Page 141 !

“When the universe formed during the Big Bang 13.8 billion years ago, the chemical reactions of the aftermath formed the first molecules. Those first molecules were crucial in helping form everything we know, but they're also absent.

And although HeH+, the helium hydride ion, has been proposed for years as that first molecule, scientists couldn't find any evidence of its existence in space -- until now. The findings were published Wednesday [04/17/19] in the journal Nature.

After the Big Bang, HeH+ formed in a molecular bond when helium atoms and protons combined. Later, these would break apart into hydrogen molecules and helium atoms. Both elements are the two most abundant throughout the universe, with hydrogen first and helium second. “
https://www.cnn.com/2019/04/17/world/earliest-molecule-in-the-universe-scn/index.html

“Researchers have detected the first molecule in space that was formed after the Big Bang. Previously, they had searched for helium hydride ions for decades. The finding could help to further understanding of the early development of the universe, reports a team led by Rolf Güsten from the Max Planck Institute for Radio Astronomy in Bonn in the journal ‘Nature’.

Helium hydride ions were the first molecules to form in the universe after the Big Bang about 13.8 billion years ago. Although the existence of the ion, a compound of ionised hydrogen and helium, was shown in the laboratory as early as 1925, it remained undetectable in space for a long time. ‘To date, there have simply been no appropriate detectors’, said astrophysicist Güsten."
http://www.general-anzeiger-bonn.de/ga-english/Researchers-from-Bonn-determine-the-oldest-molecule-in-space-article4090654.html

“The lack of evidence of the very existence of helium hydride in interstellar space was a dilemma for astronomy for decades,” says Rolf Guesten of the Max Planck Institute for Radio Astronomy, in Bonn, Germany, and lead author of the paper, in a press statement.

The dilemma was solved by NASA’s Stratospheric Observatory for Infrared Astronomy, or SOFIA. The world’s largest airborne observatory, SOFIA is an 80/20 partnership of NASA and the German Aerospace Center (DLR). It's an airplane—an extensively modified Boeing 747SP aircraft carrying a 2.7-meter (106 inch) reflecting telescope.

Helium hydride has long presented challenges to scientists. In the late 1970s, while studying a planetary nebula called NGC 702, a growing suspicion formed that it could be a cradle for this earliest of molecules. But nothing, not even space telescopes, could clear the noise of the nebula for the specific signal of helium hydride.

So scientists turned to SOFIA. The plane flies at 45,000 feet, above the interfering layers of the Earth's atmosphere. While it can't get as close to objects in space as the Hubble, it does have one serious advantage—it can come back to Earth. That means scientists can make adjustments based on why they are searching the skies. …

One of those instruments is known as the German Receiver at Terahertz Frequencies, or GREAT. Scientists were able to alter GREAT by adding a channel specifically geared towards helium hydride. Similar to a radio receiver, GREAT was able to tune into the frequencies generated by helium hydride molecules.”
https://www.popularmechanics.com/space/deep-space/a27194188/nasa-oldest-molecules-in-the-universe/

“The Big Bang itself produced just a handful of elements (variations of hydrogen, helium and lithium nuclei), so researchers have a pretty good sense of what the first atoms and molecules might have been. But the very first molecular bond to form, linking together atoms of different elements in a single molecule, has long been missing in action.

Known as a helium hydride ion (HeH+), this conglomeration of basic bits is just a helium atom and a hydrogen’s nucleus (aka a proton) stuck together. As the first compound created in the universe, you’d expect there to be traces of it throughout the universe — but astronomers couldn’t find it. (Scientists managed to produce some in the lab in 1925, so at least they knew it wasn’t an impossible substance.)”

http://www.astronomy.com/news/2019/04/astronomers-find-oldest-type-of-molecule-in-space

“SOFIA took three flights in May 2016, climbing as high as 45,000 feet, to observe the planetary nebula NGC 7027, Maria Temming reports for Science News. Positioned about 3,000 light-years away, the planetary nebula is an expanding cloud of gas surrounding a star that was once similar to the sun but has ejected most of its material, leaving behind a stellar remnant called a white dwarf. Within the hot gas of the nebula, SOFIA was able to pick out the signature of helium hydride in infrared light. …

Helium hydride is not a particularly stable molecule, but scientists were able to create the positively charged ion in the lab in 1925, reports Bill Andrews for Discover. Astronomers have hoped to find the molecule in a nebula for decades, and in the 1970s, observations of NGC 7027 suggested that it might have the right conditions—high heat and large amounts of ultraviolet radiation—for helium hydride to form.

More recently, an upgrade to one of SOFIA’s instruments, the German Receiver at Terahertz Frequencies (GREAT), allowed the airborne telescope to search for the wavelength of light emitted by helium hydride ions. The instrument works like a radio receiver, according to the NASA statement, and telescope operators can tune to the correct frequency to search for specific molecules.

The helium hydride observed by SOFIA was formed in NGC 7027, long after the first molecules were created more than 13 billion years ago. But the lead author of the new study, Rolf Güsten of the Max Planck Institute for Radio Astronomy in Germany, and his team plan to use the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile to search for helium hydride that was created shortly after the big bang. If they are successful, humanity will have peered back in time billions of years and spotted some of the first building blocks of everything that was to come.”
https://www.smithsonianmag.com/smart-news/nasas-flying-telescope-spots-oldest-type-molecule-universe-180972000/

“Adam Perry, who studied helium hydride while at the University of Illinois Urbana-Champaign, likens the new find to unearthing a fossil that fills a missing link in animal evolution. “Everybody knew [helium hydride] had to be out there,” says Perry, who wasn’t involved in the study. But ‘where before there wasn't any hard evidence, now there is.
… People who do astrochemistry are going to be very excited about this.’

Studying the helium hydride ions in NGC 7027 may offer new insights into the chemical reactions that form these ions, says study coauthor Rolf Güsten, an astrophysicist at the Max Planck Institute for Radio Astronomy in Bonn, Germany.
Güsten and colleagues also hope to use the Atacama Large Millimeter/submillimeter Array in northern Chile to scour the distant, early universe for helium hydride ions born soon after the Big Bang.

'Helium hydride is a finicky molecule. Helium itself is a noble gas making it very unlikely to combine with any other kind of atom. But in 1925, scientists were able to create the molecule in a laboratory by coaxing the helium to share one of its electrons with a hydrogen ion.

Then, in the late 1970s, scientists studying the planetary nebula called NGC 7027 thought that this environment might be just right to form helium hydride. Ultraviolet radiation and heat from the aging star create conditions suitable for helium hydride to form. But their observations were inconclusive. Subsequent efforts hinted it could be there, but the mystery molecule continued to elude detection. The space telescopes used did not have the specific technology to pick out the signal of helium hydride from the medley of other molecules in the nebula.”
https://www.sciencenews.org/article/first-type-molecule-form-universe-has-been-seen-space

About 2/3 down the page is a 1 ½ minute video describing the existence of hydrogen-hydride:
https://www.nasa.gov/feature/the-universe-s-first-type-of-molecule-is-found-at-last

“HeH+ is the strongest known acid on Earth and was first synthesized in a lab in 1925. Because it is made from hydrogen and helium — the two most abundant elements in the universe and the first to emerge from the nuclear reactor of the Big Bang 13.8 billion years ago — scientists have long predicted that the molecule was the very first one to form when the cooling universe allowed protons, neutrons and electrons to exist side by side in atoms.

Scientists can't rewind the universe to hunt for this fledgling molecule where it was born, but they can look for it in parts of the modern universe that best replicate those superhot, superdense conditions — in the young nebulae of gas and plasma that explode out of dying stars.

These so-called planetary nebulae form when sun-like stars reach the end of their lives, blast away their outer shells and shrivel into white dwarfs to slowly cool into crystal balls. As those dying stars cool, they still radiate enough heat to strip nearby hydrogen atoms of their electrons, turning the atoms into the bare protons that are required for HeH+ to form.

Detecting HeH+ in even the closest planetary nebulae to Earth is tricky, because it glows at an infrared wavelength that is easily obscured by our own planet's atmosphere. In the new study, researchers got around that atmospheric haze by using a high-tech telescope mounted on a moving aircraft called SOFIA (the Stratospheric Observatory for Infrared Astronomy).”
https://www.livescience.com/65256-first-molecule-in-the-universe.html

You may want to use an article from those attached to write an Essay question for your Final Exam.

*This Blog contains several entries that would be helpful to your chemistry classroom. Check out the Topic List to help you to find past Blog entries.

Also, Write To Me about your successes, challenges, or questions in the Chemistry Classroom.

Remember, buying a copy of the lab book Chemistry on a Budget can be very useful to your Chemistry classroom with labs and class article ideas.

Have a great weekend!

0 Comments

Britain goes one week without burning coal

5/17/2019

0 Comments

germany shuts down coal plants

5/10/2019

0 Comments

The book Chemistry on a Budget contains inexpensive chemistry labs that are useful with easy to obtain materials.

There are two versions of each lab, one with a ten-question conclusion and one with directions for a full lab report. This way the teacher has the option! Each lab is two pages to allow for one two-sided handout.

A 5-Star Customer Review of Chemistry on a Budget at amazon.com states:

“[S]traight forward, to the point, using household chemicals… this is the lab book for you.
I teach high school chemistry and this is exactly what I was looking for. Labs included simple household chemicals that could be easily found. Nice format, easy to follow along procedures, and touches on every topic of our chemistry curriculum.”

You can buy this lab book for $23 at amazon.com or lulu.com. It will take 1-2 weeks to get to you -- Order Now. It’s a great resource!

http://www.amazon.com/Chemistry-Budget-Marjorie-R-Heesemann/dp/0578129159/ref=sr_1_1?s=books&ie=UTF8&qid=1389410170&sr=1-1&keywords=chemistry+on+a+budget

http://www.lulu.com/shop/marjorie-r-heesemann/chemistry-on-a-budget/paperback/product-21217600.html

*Some of you have already purchased my lab book – be sure to check out Page 141 !

“Germany, one of the world’s biggest consumers of coal, will shut down all 84 of its coal-fired power plants over the next 19 years to meet its international commitments in the fight against climate change, a government commission said Saturday [1/26/2019].

The announcement marked a significant shift for Europe’s largest country — a nation that had long been a leader on cutting CO2 emissions before turning into a laggard in recent years and badly missing its reduction targets. Coal plants account for 40% of Germany’s electricity, itself a reduction from recent years when coal dominated power production.”
https://ktla.com/2019/01/27/germany-to-close-all-coal-fired-power-plants-to-rely-primarily-on-renewable-energy/

"Germany will spend tens of billions of dollars to end its use of coal power within two decades, if a plan agreed to early Saturday by representatives of the power industry, environmental movement, miners and local interest groups becomes official policy.

The deal, hammered out after more than 20 hours of intense, often fractious negotiating among a 28-member commission appointed last year by Chancellor Angela Merkel, would be one of the most significant energy transformations a nation has yet attempted in the face of climate change.

Thirty countries have already set out proposals to cut their carbon emissions by eliminating coal, the dirtiest and cheapest fossil fuel, including Britain, Canada and Sweden. But none of those plans are of the scale laid out in Germany, an industrial giant that currently relies on coal for almost a third of its energy needs."
https://www.nytimes.com/2019/01/26/world/europe/germany-quit-coal-2038.html

“Germany long saw itself as a global leader in fighting climate change but was forced to concede in recent years that it would by miss its target date of 2020 to reduce CO2 emissions by 40% from 1990. It is expected to be 32% below 1990 levels by next year.

Germany and nearly 200 nations around the world agreed to the landmark Paris climate accord in 2015 to work to keep global warming ‘well below’ 2 degrees Celsius and pursue efforts to limit the rise to 1.5 degrees. The planet has already warmed by about 1 degree Celsius since pre-industrial times as a result of the human-caused build-up of greenhouse gases. Scientists say the world is already experiencing the consequences in the form of rising sea levels, more intense hurricanes and wildfires.

Despite its stumbles in recent years that led critics to accuse Germany of hypocrisy, Kemfert said Saturday’s decision will make it likely that Germany can meet the target of a 55% reduction from 1990 CO2 levels by 2030 and an 80% reduction by 2050.

‘It’s good that Germany now has a clear road map for the phase-out of coal and we’re on the path to becoming carbon-free,’ said Martin Kaiser, executive director of Greenpeace Germany and a member of the commission. He was also pleased that the commission recommended that utilities scrap plans to clear the last 250 acres of the Hambach Forest west of Cologne for a lignite open-pit mine. …

Included in the recommendations was that the phase-out target be reviewed every three years. Also, the final deadline could be moved forward, if possible, by three years to 2035.

The initial targets are considerable, calling for a quarter of the country’s coal-burning plants with a capacity of 12.5 gigawatts to be shut down by 2022. That means about 24 plants will be shut within the first three years. By 2030, Germany should have about eight coal-burning plants remaining, producing 17 gigawatts of electricity, the commission said.”
https://www.latimes.com/world/europe/la-fg-germany-coal-power-20190126-story.html?fbclid=IwAR01a-ILAaio_Bsj2jqlLk7vbFDVYNyNfwh4L3-izp78fdTNiKR_E1nXfDU

“The announcement marked a significant shift for Europe’s largest country — a nation that had long been a leader on cutting CO2 emissions before turning into a laggard in recent years and badly missing its reduction targets. Coal plants account for 40% of Germany’s electricity, itself a reduction from recent years when coal dominated power production. …

The plan includes some $45 billion in spending to mitigate the pain in coal regions. The commission’s recommendations are expected to be adopted by Chancellor Angela Merkel’s government.

‘It’s a big moment for climate policy in Germany that could make the country a leader once again in fighting climate change,’ said Claudia Kemfert, professor for energy economics at the DIW Berlin, the German Institute for Economic Research. ‘It’s also an important signal for the world that Germany is again getting serious about climate change: a very big industrial nation that depends so much on coal is switching it off.’

The decision to quit coal follows an earlier bold energy policy move by the German government, which decided to shut down all of its nuclear power plants by 2022 in the wake of Japan’s Fukushima disaster in 2011. …

Twelve of the country’s 19 nuclear plants have been shuttered so far.

The plan to eliminate coal-burning plants as well as nuclear means that Germany will be counting on renewable energy to provide 65% to 80% of the country’s power by 2040. Last year, renewables overtook coal as the leading source and now account for 41% of the country’s electricity.

German CO2 emissions fell appreciably in the early 1990s, largely because of the implosion of Communist East Germany and its heavily polluting industry. Still, the country continued to rely on coal-fired plants for a significant share of its electricity.

Powerful utilities and labor unions helped keep coal-burning plants operating and previous governments even planned to expand the number of coal plants to compensate for the pending withdrawal from nuclear power. There are still about 20,000 jobs directly dependent on the coal industry and 40,000 indirectly tied to it.

Cheap and abundant, coal is the world’s leading source of energy to produce electricity and will remain so despite Germany’s exit.

The panel that made the recommendation to close coal plants included leaders in the federal and state governments along with top industry and union representatives, scientists and environmentalists.

Germany long saw itself as a global leader in fighting climate change but was forced to concede in recent years that it would by miss its target date of 2020 to reduce CO2 emissions by 40% from 1990. It is expected to be 32% below 1990 levels by next year.

Germany and nearly 200 nations around the world agreed to the landmark Paris climate accord in 2015 to work to keep global warming 'well below' 2 degrees Celsius and pursue efforts to limit the rise to 1.5 degrees. The planet has already warmed by about 1 degree Celsius since pre-industrial times as a result of the human-caused build-up of greenhouse gases. Scientists say the world is already experiencing the consequences in the form of rising sea levels, more intense hurricanes and wildfires.

Despite its stumbles in recent years that led critics to accuse Germany of hypocrisy, Kemfert said Saturday’s decision will make it likely that Germany can meet the target of a 55% reduction from 1990 CO2 levels by 2030 and an 80% reduction by 2050.”
https://www.fafcosolar.com/solar-news/germany-fights-against-climate-change/

“Germany gets more than a third of its electricity from burning coal, generating large amounts of greenhouse gases that contribute to global warming.”
https://www.apnews.com/3887fa40ea4a4d4fab721c3779a1bec9

“Shuttering the rest of Germany’s coal-fired power capacity could cost taxpayers another $2.3 billion per year, The Financial Times reported. The government commission recommended policies to shield ratepayers from cost increases, but it’s unclear if that could realistically be done.

If all goes to plan, Germany will decrease its coal capacity from roughly 42 gigawatts today to 30 gigawatts by the end of 2022, then to 17 gigawatts by 2030. By 2038, all Germany’s coal plants will be closed, according to the plan.”
https://dailycaller.com/2019/01/28/germany-coal-plants-closing-global-warming/

The following 1:45 minute video provides an overview of Germany’s plan:
https://www.youtube.com/watch?v=IWaU9l_1sUE

*This Blog contains several entries that would be helpful to your chemistry classroom. Check out the Topic List to help you to find past Blog entries.

Also, Write To Me about your successes, challenges, or questions in the Chemistry Classroom.

Remember, buying a copy of the lab book Chemistry on a Budget can be very useful to your Chemistry classroom with labs and class article ideas.

Have a great weekend!

0 Comments