Sham,+Aakash

In this I learn that the HF is so dangerous to skin because the F looks for an electron to bind to, it binds to electrons in skin cells. Also since the HF is neutrally charged, it can pass through the fatty surface of the skin and move to the epidermis, where it can bind with the electrons there. I learned that pain is created when the HF reacts with skin, specifically the Ca and the Mg. When these react it can cause nerves to fail and cell membranes to collapse. I learned that if enough of the Ca or Mg is reacted with, it can cause death.

In this article of the Greek terminology, I found it interesting that so many of the name for atoms are named because of chemical properties that they have, such as Hydo + Gen which means water former, as hydrogen forms water when it burns. Something else that I thought was interesting was that the prefixes that are used for molecules and polyatomic ions were Greek, such as -per for ions like perchlorate. A third interesting thing I found was that terms for all types of chemistry and even everyday words are formed from Greek words.

I read the article on solar energy. I found it interesting how the solar cells convert light waves in to energy. The solar cells are made out of silicon crystal material. The light waves hit the electrons in the bonds shared by the atoms, and the electrons get energized. The electrons then move up to a higher energy cell, where they are allowed to move more freely. This creates a current and thus electricity. There are newer solar panels using smaller crystals made of different compounds, but these are not as good at creating electricity as the silicon crystal material.

Aakash, Good post! Solar panels will be around for a while and will continue to improve. MW

Polymers in the Field

I found it interesting how the turf and track absorb the heat so greatly. The polymer chains must absorb more heat than normal ground is able to, making it hotter. I also found interesting how the track or turf can be cooled like skin on humans with water. It makes sense that it would considering that water has a relatively high specific heat so when placed it absorbs all the heat and then evaporates, taking the heat with it. Another thing I found interesting is that there are microbes in normal soil that decompose things that can cause infection. This could definitely pose a problem for anyone playing on the turf, since this bacteria does not go away.

Good post Aakash. I wonder about the bacteria as well! MW

Oil and Water

There were some things in the article I already knew such as the fact that oil is less dense that water, and this causes it to be on top. I also knew that water has hydrogen bonding present because of the hydrogen atoms that are bonded to the oxygen atoms. A third thing that I already knew was oil was non-polar. What I did not know was each oil molecule is attracted to other water molecules more that it's fellow oil molecules, because water induces a dipole moment in the oil. Also I did not know that oil would rather be with the water, than with other oil molecules because the induced dipole that the water creates is stronger than the intermolecular forces present between each oil molecule. Also I did not know that when polar molecules, such as water, are placed on a non-polar surface they bead up, where as if a non-polar substance is placed on polar molecules, it spreads out into a extremely thin layer.

Aakash, Well done. 5 stars! MW

Salt on the Roads

I found it interesting that when a salt water solution freezes, it is just the water that freezes and not both the water and salt ions. It would make sense that more energy be removed in order for only the water to freeze. I also found it interesting that once the solution is frozen, the temperature must continually be lowered in order to keep it frozen, because as the water freezes, the ion concentration goes up, requiring more energy to be removed. I also found it interesting how the salt melts already formed ice. It does it because the molecules on the surface of the ice move about more than the inner molecules and react more. So the salt reacts with some of the ice and forms a solution and then a snowball like effect takes place. The salt solution keeps melting more ice at a faster rate. So while it starts slow, it gets faster as more ice is melted by the salt reacting with the water molecules.

Hand Warmers

Some things that I already knew were that hot stones were used in earlier times as stones absorb heat and release it, like brick floors in sun rooms that gather heat in the day and release it later, saving you money on your heating bill. I also knew that the reaction inside the hand warmers is exothermic, other wise it would get cold and unpleasant. A third thing I knew was that the reaction in the hand warmers is set off in the presence of oxygen from the air, and this is why it is sealed tight. Some things I did not know were that the oxygen from the air reacts with the iron to essentially form rust inside the package. Also I did not know that the material of the pouch itself makes a difference in the reaction, although now it makes sense that if the pouch is more permeable, then more oxygen can get in and the reaction is faster. A third thing I learned was that reusable hand warmers use NaC2H3O2. This releases heat as it crystallizes and then can be boiled to revert the process and be reused.

Aakash,

Well done! 5 stars. MW

Somethings I already knew were that the sap contains both water and sugar, such as sucrose. I knew that the sap had to be tapped from the trees. A third thing I knew was that the sap had to be heated to evaporate the water in the sap to get the pure syrup. I did not know that sucrose had two saccharides in it, fructose and glucose. I also did not know that the sap was slightly acidic containing acids such as oxalic acid. A third thing I did not know was that trace amounts of minerals like potassium and magnesium are in the sap and can form precipitates at the end of the process.

Aakash, Looks good! 5 stars. MW

Some things I knew include that oxidation is an atom losing electrons and that reduction is the gain of electrons. Also I knew that an anode is a metal that gives up electrons and that a cathode accepts electrons. I knew that without a (salt) bridge this process (rusting) would not occur. I was not aware that cars rust in coastal areas faster, because of the salt in the air, although with my new knowledge about electro-chem, it makes perfect sense. Also I did know that iron oxide was a thermodynamically preferred state than just regular iron. A third thing I did not know was that paint could prevent the connection of the anode and cathode, thus preventing corrosion. I guess I should keep my car nice and painted.

Aakash, Yes a break in the paint should be fixed right away! 5 rust-free stars! MW