Diver Silicone
How Rare and Inert are the Noble Gases?
Elements of group 18 of the present day periodic table are now collectively known as Noble Gases as they are the most stable gaseous elements due to the fact that they not only have the maximum number of valence electrons that their outer shell can hold, but also they rarely react with other elements, and are used in many conditions when a stable element is needed to maintain a safe and constant environment. As their name ‘Rare gases’ suggests, the noble gases are rather uncommon on Earth. Collectively, they make up about 1 percent of Earth's atmosphere. Most of the noble gases have been detected in small amounts in minerals found in Earth's crust and in meteorites. They are thought to have been released into the atmosphere long ago as by-products of the decay of radioactive elements in Earth's crust.
Of all the rare gases, namely: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn), argon is present in the greatest amount. It makes up about 0.9 percent by volume of Earth's atmosphere. The other noble gases are present in such small amounts (there are only 5 liters of helium in every million liters of air) that it is usually more convenient to express their concentrations in terms of parts per million (ppm). But contrary to it, helium is much more abundant in the outer space. In fact, next to hydrogen, helium is the most abundant element in the universe. About 23 percent of all atoms found in the universe are helium atoms.
Though Radon is present in the atmosphere in only trace amounts, higher levels of radon have been measured in homes all over the United States. It can be released from soils containing high concentrations of uranium, and they can be trapped in homes that have been weather sealed to make heating and cooling systems more efficient. Radon testing kits are commercially available for testing the radon content of household air. Most of the rare gases are obtained commercially from liquid air. As the temperature of liquid air is raised, the rare gases boil off from the mixture at specific temperatures and can be separated and purified. Although present in air, helium is obtained commercially from natural gas wells where it occurs in concentrations of between 1 and 7 percent of the natural gas.
All the noble gases are colorless, odorless, and tasteless. They exist as monatomic gases, which mean that their molecules consist of a single atom. The boiling points of the noble gases increase in moving down their group in the periodic table. Thus Helium has the lowest boiling point of any element and it has no melting point because it cannot be frozen at any temperature. The most important chemical property of the noble gases is their lack of reactivity. Helium, neon, and argon have not been found to combine with any other elements to form compounds as yet. It has been only in the last few decades that some compounds of the other rare gases have been prepared. In 1962 English chemist Neil Bartlett succeeded in preparing a compound of xenon, xenon platinofluoride (XePtF6), as the first compound of a noble gas. Since then, many xenon compounds containing mostly fluorine or oxygen atoms have been prepared. Krypton and radon have also been combined with fluorine to form simple compounds. Because some noble gas compounds have powerful oxidizing properties, they have been used to synthesize other compounds. The low reactivity of the noble gases can be explained by their electronic structure. The atoms of all six gases have outer energy levels containing eight electrons, the arrangement that chemists believe the most stable arrangement an atom dreams to have. Because of these very stable arrangements, noble gas atoms have little or no tendency to gain or lose electrons, which they would have to do in order to take part in a chemical reaction.
As is the case with all substances, the uses to which the noble gases are put reflect their physical and chemical properties. For example, helium's low density and inertness make it ideal for use in lighter-than-air crafts. Moreover, because of the element's very low boiling point, it has found many applications in low-temperature research and technology. Divers breathe an artificial oxygen-helium mixture to prevent the formation of gas bubbles in their blood as they swim to the surface from great depths. Other uses for helium have been in supersonic wind tunnels, as a protective gas in growing silicon and germanium crystals and, together with neon, in the manufacture of gas lasers.
Neon is well known for its use in neon signs. Glass tubes of any shape can be filled with neon. When an electrical charge is passed through the tube, an orange-red glow is emitted. By contrast, ordinary incandescent light bulbs are filled with argon. Because argon is too inert to react with the hot metal filament and prolongs the bulb's life. Argon is also used to provide an inert atmosphere in welding and high-temperature metallurgical processes. By surrounding hot metals with inert argon, the metals are protected from potential oxidation by oxygen in the air. Krypton and xenon also find applications in commercial lightings. Krypton can be used in both incandescent light bulbs and fluorescent lamps, both of which are also employed in flashing stroboscopic lights that outline commercial airport runways. And because they emit a brilliant white light when electrified, they are used in photographic flash equipment. Radon has registered its applications in medical -radiotherapy due to its radioactive nature. Ar is used for optical and mass spectrometry as the plasma gas. Other noble gases are used for plasma spectrometry including the for improved detection limits of Cl. Current studies are being conducted to see if there are improved detection limits for any other elements on the periodic table with the use of other noble gases. The problem with Kr and Xe is that they are quite expensive.
About the Author
Dr.Badruddin Khan teaches Chemistry in the University of Kashmir, Srinagar, India.
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An Early Halloween Celebration
Now that October is just around the corner after a very short summer, it is time to prepare for fall festivities and scary movies. I look forward to going apple picking and attending fall fairs, going to the Christmas Tree Shoppe to stock up on fall decor and, of course, curling up on cold weekend nights for some good horror movies!
I started to think about how I can start the Halloween experience early, so I decided that I'm going to invite a few friends over this weekend for a fun night of horror! I'm not going crazy on creepy decorations just yet, but we'll certainly light a few candles to set the ambiance. I was thinking of preparing a delicious dinner, followed by two horror movies then a little good night story for my friends before they leave for the evening. I should mention that my daughter is going to be at her grandmother's house while this is happening! So far, I have found some great recipes from Food Network to share with you for the dinner and treats.
Appetizers To add some Halloween color into the mix, I'm going to make this appetizer that includes a witch green color.
Roasted Chile Guacamole with Baked Tortilla Chips Baked Tortilla Chips:
• Cooking spray • 3 sun-dried tomato basil tortilla wraps • 3 garden spinach herb tortilla wraps • Olive oil • Salt and pepper Guacamole: • 1/2 cup frozen chopped onion, thawed • 2 cups frozen no-salt added petite peas, thawed • 1/3 cup water • 2 tablespoons lemon juice • 1 (1-ounce) packet guacamole seasoning mix • 1 teaspoon chopped garlic • 1/2 cup diced tomatoes with no-salt added • 1 cup chopped avocado • 1 (7-ounce) can fire roasted diced green chiles
For tortillas chips: Directions: Preheat oven to 350 degrees F. Spray a baking sheet with cooking spray; set aside. On a cutting board, stack 3 tortillas and using a sharp knife, cut into 8 wedges (like a pie). Repeat with remaining tortillas. Separate any that may stick together. Place on baking sheet, evenly spaced. Drizzle with olive oil and season with salt and pepper. Bake for 8 to 10 minutes or until golden. Remove and let cool.
For Guacamole: In a medium saucepan combine onions, peas, water, lemon juice, guacamole seasoning, and garlic. Cook for 10 minutes until ingredients are soft. Remove from heat and let cool. Pour cooled pea mixture into a large bowl. Add avocado and mash with a fork or potato masher. Strain tomatoes and add to bowl with green chilies. Mix until blended. Serve with baked chips.
Since my good little doobie will be at her grandmother's house, I can also make a few drinks to accompany our appetizers! I'm thinking I'll go with Emeril's Tin Can Margaritas Ingredients: • 1 lime, cut in wedges • Coarse salt, for glasses • 1 large can frozen limeade • 1 full can good-quality tequila • 1/2 can triple-sec • 1/2 can lemon juice • Ice Directions: Rub rims of glasses with a lime wedge; place salt in a saucer and dip rims. In a pitcher combine remaining ingredients, stir well and fill up with ice. Serve in salt-rimmed glasses with lime wedges.
And now...for the main course...Pumpkin-Peanut Curry Noodles with Five-Spice Seared Scallops and Shrimp, which only takes 20 minutes to cook (believe it or not)!
Ingredients: • 1 pound spaghetti • Salt • 5 tablespoons vegetable oil or peanut oil • 3 cloves garlic, finely chopped • 2 inches ginger root, minced or grated • 1 red bell pepper, thinly sliced • 1/2 teaspoon crushed red pepper flakes • 1/4 cup creamy peanut butter • 1/4 to 1/3 cup tamari dark soy sauce, eyeball it • 1 (15-ounce) can cooked pumpkin • 2 rounded tablespoonfuls mild or hot curry paste (recommended: Patak's) found on international foods aisle • 3 tablespoons five-spice powder • 12 jumbo shrimp, peeled and deveined • 12 diver scallops, trimmed and patted dry • 4 scallions, cut into 2-inch pieces, then thinly sliced lengthwise into matchsticks Directions: Heat a large pot of water for noodles. When water boils, salt it and add pasta to cook to al dente or with a bite to it.
While pasta cooks, heat a large, deep skillet over medium heat with 2 tablespoons vegetable or peanut oil. Add garlic, ginger, red bell pepper, and pepper flakes to the pan and cook together a couple of minutes, then add peanut butter and melt it. Whisk soy into peanut butter, then stir in pumpkin and curry paste. The sauce will be very thick. Turn down the heat to low. Add a ladle or 2 of pasta cooking water to thin sauce a bit and simmer over low heat. Adjust salt, to taste.
Heat a small to medium skillet over high heat. Pour the five-spice powder onto a plate with some salt. Press both sides of the shrimp and scallops into the powder. Add 3 tablespoons of remaining oil to hot skillet. Place the shrimp in the pan and cook 1 minute, flip and sear the other side until just opaque. Remove shrimp to a plate and set aside. Add another 3 tablespoons of oil to the skillet and heat back up to smoking. Add the scallops and sear on both sides until opaque. Remove scallops and add to the plate of shrimp.
Drain pasta and return pasta to the pot. Add the curry-pumpkin sauce and toss thoroughly. Serve noodles on 4 plated and top with scallions and seafood. All I have to say is YUM! And now for dessert...Dirt Pudding! This literally takes 5 minutes! Have some pudding prepared from the night before, crack open a package of Oreos and crumble the cookies into the pudding. It's delectable and easy. It is now time for the feature presentation: Movie number 1: Scream Intermission: Coffee with Baileys Irish Cream, Amaretto and Frangelico Movie number 2: From Dusk Till Dawn
Good night story: This woman was doing laundry on a Saturday morning while her husband was at work. For some reason every time she pushes her clothes into the washing machine, she gets the feeling that someone is behind her, but she keeps going, admitting the thought is ridiculous. The basement never bothered her before. It isn't musty as there's a dehumidifier down there. It hasn't been emptied for a while but the air is still dry. The cobwebs are always dusted and swept away as she is not fond of spiders, so the basement is fairly clean minus a few bags and it's bright enough so there are no unlit corners. She hears her son rummaging through something in the living room upstairs, so she quickly goes back upstairs to be sure he is being safe.
Her son decided to try out his new roller-skates while mom was downstairs. The lady reminded her son that he needs to wear a helmet and kneepads if he wants to roller-skate then he can join her in the basement while she washes clothes. There is more room to skate in the large space downstairs. The husband had just recently finished ripping the rug off the basement stairs so he can replace it and there are small nails sticking out of the front of a few of the stairs. The mom tells her son that she'll carry him downstairs because he's already wearing his skates and she doesn't want him to get hurt on the nails. The son complies.
Once the son's helmet and kneepads are on, the mom sets him free to skate about the basement. Then she gets this horrible chill down her spine and a sick feeling in her stomach so she takes a minute to lean up against the table where she folds her clean clothes. She can't figure out what the problem is, but her father is in the hospital so she decides to call her mom from the cell phone she has in her sweatshirt pocket to be sure everything is okay with him. Her mom said that everything is good and that her dad will be coming home the next day. Her dad fell and one of his toenails was caught on something and had been ripped off completely. He is a heavy man and any fall he takes is sure to cause some damage, but hooking his toenail on something made it even worse.
"He's fine", she thought, "so what can this horrible feeling be?" Her son is skating as fast as he can while holding onto the basement wall. She covers her face with her hands trying to think of what the problem could be. All of a sudden her son catches one of his skates in the grate of the basement drain. His skate stays there and his body goes flying forward. He luckily landed on a trash bag that was full of clothes the mom put down there a week ago for the Salvation Army.
She dashes to her son who is crying out of shock from falling with his new skates. She comforts him and walks over to retrieve his skate, still stuck in the grate of the drain. "These crazy plastic roller-skates. We'll get you a new pair today, baby". She looks back down at the skate and notices something hairy sticking out of the drain along with a foul odor.
She calls her husband to come home from work on his break to check this out. She puts on a movie upstairs for her son who is ready for a nap. Her husband gets home shortly after and hurries with her to the basement to see what she was talking about. He grabs a crow bar that was stashed behind the dryer and pries open the drain, catching a bunch of hair along the way and flinging the object across the room once the grate breaks free. It thumps against the wall and falls behind the trash bags full of clothes. They notice that whatever it is, it's bleeding because there is a splat of blood on the wall. "I wish I had my father check that drain when he was down here last weekend. You know how I like to keep that clean".
They tiptoe over to where the object had thumped to the ground and peeked behind the bags. They scream and jump back when they realize it's a human head with skin that is falling off from spending so much time in the drain water. They panic and the husband takes a good look to make sure they didn't miss anything else down there. He noticed her father's pocketknife under the basement stairs with blood on it. He does not pick it up. As he examines the stairs for further evidence, he sees what he originally thought was a leftover piece of the carpet he had ripped up and notices that it's a toenail. "Get upstairs and call the police!"
The wife calls the police who eventually get there and investigate her basement. They observe the head and ask them what is in the bags that are on the floor. The lady tells them that they're stuffed with clothes. They open the bag and notice body parts that have been hacked up and stuffed in quilts. They take the toenail as evidence.
Goodie Bags to Take Home: Some fun trinkets from iParty along with some cool Halloween lollipops! Ingredients: • 6 or 8-inch wooden pop sticks • Gummy worms, as needed • 2 cups sugar • 2/3 cup corn syrup • 2/3 cup water • 1/4 teaspoon vanilla extract • 1/4 teaspoon orange, lemon or cherry extract • Few drops orange food coloring Directions Lay a silicone sheet on a baking pan, place the sticks on the pan and place 3 pieces of gummy Worms above the tip of each stick to form a gummy worm triangle. Combine the sugar, corn syrup, and water in a clean, dry small saucepan. (It is best to use a heavy gauge pan and preferably with a pour spout.) Bring to a boil over high heat and cook without stirring until the mixture reaches 305 degrees F or "hard crack" stage on a candy thermometer. Occasionally wash down the sides of the pan with a clean pastry brush dipped in water to remove any sugar crystals that are clinging to the sides of the pan.
When the mixture reaches 305 degrees F, remove the pan from heat and dip the bottom of the pan into an ice bath for a few seconds to stop the candy from cooking. Add the extracts and food coloring and stir very gently with a wooden spoon so the color is evenly distributed. Pour the syrup over the gummy worms and just over the stick. Cool the candy for at least 20 minutes. Lift the lollipops off the silicone and either serve immediately or wrap in an airtight container. Now, tell me I can't plan an awesome night of fun with a few close friends!
About the Author
Frank helps people learn about Dish Network Satellite TV, and how they can save money every month with popular Dish Network Packages. Dish has advanced, award winning, Dish DVR and Dish HD receivers, there is a lot of good news to share. Frank and his team also help people determine if satellite internet is right for them and, if so, helps explain the offers from WildBlue and Hughesnet
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