Quickie Questions - Physics - Chemistry

Date Answered Questioner (age, location) Question Answer
December 30, 2009kyle (missouri)What two chemcials expand when put together? If you know, what are the names?There are many, but hydrocarbons and oxygen are near the top of energetic reactions.
October 19, 2009Kassy (Fort worth)Where is the metals located on a Periodic tableThe periodic table is divided into three main sections: the metals, the nonmetals, and the metalloids. Alkali Metals are in the first column of the periodic table, Alkaline Earth Metals are in the second column of the table, Transition Metals are located between columns IIA and IIIA in the periodic table. See this page for more information.
October 16, 2009Phoebe (Belize)How many bromine molecules are there with different masses? and which of the molecules would you expect to evaporate most quickly from liquid bromine?The possible combinations of the two isotopes in a diatomic molecule (Br2), are: 79-79, total molecular weight of 158 79-81 (or 81-79), total molecular weight of 160 81-81, total molecular weight of 162
September 14, 2009Imran (Dubai UAE)is there any element in chemistry with symbol D ?As far as I know there are only Db (Dubnium), Ds (Darmstadtium), and Dy (Dysprosium). There is none identify with a single D.
July 30, 2009Anna Claire (Virginia)What is a metalliod ?Metalloids or semi-metals are found between metals and nonmetals on the Periodic Table of Elements. They have characteristics that resemble both metals and nonmetals.
April 21, 2009sophie (london)what is the mass of an oxygen molicule?The exact mass of oxygen-16 (the most common oxygen isotope) is 15.9949 u, and the average atomic mass of natural oxygen is 15.9994 u.
March 5, 2009anish (nepal)what exactly is an alkali?Any strongly basic substance of hydroxide and carbonate, such as soda, potash, etc., that is soluble in water and increases the pH of a solution.
February 8, 2009samiye (United States)how are periodic elements groupedThere are several ways to group the elements in the periodic table. They are commonly divided into metals, semimetals, and nonmetals. There are also more specific groups, like transition metals, rare earths, alkali metals, alkaline earths, halogens, and noble gases.
January 20, 2009hasnain (madina,saudi arabia)what mean by ozone?The oxygen we breath is a molecule composed by two atoms of oxygen (O2). Ozone has three atoms of oxygen (O3).
January 14, 2009chloe bowker dargue (united kingdom)what happens to objects at 85 degrees celciusIt depends of the substance they are made of. For example, water will only get hot, but Celsium would have melted. (Celsium Melting point: 28.4oC)
January 13, 2009Adam (England)What are the signs of a chamical reaction?Chemical rections can produced many signals: heat, light, sound, new substance produced, etc.
April 2, 2008Christa (Mississippi/USA)What can you tell on the reaction of baking soda and acids?When an alkali substance is placed in an acid, an acid/baking soda reaction occurs. This is the case when putting in contact baking soda (alkali) and an acid (like vinegar, for example). This chemical reaction releases carbon dioxide gas.
March 3, 2008georgia wayda (illinois)which element comes first when writing a chemical formula?Here are clear instructions on how to write chemical formulas.
December 21, 2007Hannah (United States)How many elements are found naturally on earth?As of 2006, The periodic table lists 117 elements. Ninety-two of then are found naturally on Earth.
December 20, 2007Devin (Iowa/United States)What is as hard as corundum?The Mohs scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer material. In this scale, corundum reaches a value of 9, only surpassed by diamond, with a 10.
December 18, 2007Forrest (SC/US)What are two physical and three chemical properties of BariumChemical Properties of Barium: Electrochemical Equivalent: 2.5621g/amp-hr Electron Work Function: 2.7eV Electronegativity: 0.89 (Pauling Heat of Fusion: 7.75kJ/mol Physical Properties of Barium Atomic Mass Average: 137.327 Boiling Point: 2171K 1898C 3448F Conductivity (Electrical): 0.03 106/cm Conductivity (Thermal): 0.184 W/cmK Density: 3.59g/cc @ 300K
February 12, 2007tin (arizona/USA)what is a polymers?The most general definition of polymer is: Large organic molecule formed by many smaller molecules in a regular pattern.
January 17, 2007laura (MO)What does ozone look like?If your question is regarding the molecule of ozone, it is very easy to represent: three oxygen atoms bound together and which is written by chemists as O3.
March 9, 2000Lorie (California, USA)What are the parts of a solution? Which is Which?The two part of a solution are the solute and the solvent. The solute is dissolved in the solvent. For example, in salt water, salt is the solute and water is the solvent.
January 11, 2000Nena (Idaho, USA)When I think of acids i think that they can hurt you, why doesn't citric acid harm you? Does the answer have anything to do with PH levels?You're on the right track. It does, in fact, have to do with levels. The PH of an acid tells how reactive it is. So if the PH is low, then it will react easily, especially with your skin!

The concentration of the acid is also very important. Citric acid is faily acidic, but there is a small amount in fruit. However, if you see a puddle of sulfuric acid I suggest you get far, far away...quickly!

December 24, 1999Bruce (Illinois, USA)Please help resolve a friendly dispute. Is it true that a tooth will dissolve in a glass of cola, or is that just an old wives' tale?If you left it there long enough, sure! However, so will anything containing phosphoric acid...orange juice, lemonade... Fortunately, people don't hold these liquids in their mouths for days on end, and saliva has a neutralizing effect as well.
October 11, 1999Steph (Pennsylvania, USA)Sublimation is when solid changes to a gas.....so what is it called when gas is changed to a solid?Sublimation is when a solid changes to a gas and deposition is when a gas changes to a solid. I hope that makes things less confusing for you.
October 11, 1999Ryan (Washington, USA)What is the difference between the measurement abbreviations ml amd mg?? (medical measurements)Ml stands for milliliter, and mg is milligrams.
A milliliter is a measure of volume, or how much space something takes up. It is usually used when measuring a liguid, like water.
A milligram is a measure of mass, or how much substance there is. It is most often used to measure solids.
September 28, 1999Daniel (Georgia, USA)What are some products made from the element Bismuth?Bismouth has a low melting point and a high boiling point. This makes it great for applications in a range of temperature. It is used mainly in the manufacure of fusible alloys. These are used in areas such as fire-protection systems, as a nuclear reactant coolant, solders, and thermopiles.
August 5, 1999Jimmy (West Virginia) How does salt melt ice on the sidewalk and yet freeze homemade ice cream?What you are observing is that salt both helps to melt ice and makes ice colder, two consistent ideas once you understand how the process works. Salt is spread on sidewalks and roads because it lowers the melting temperature of water in the form of ice to about -20C, a significant drop. If the temperature outside is above -20C, the salt will combine with the ice and melt it. However, to change from a solid to a liquid takes energy, so the salt captures thermal energy from its surroundings to fuel the melting. The melting actually causes the temperature of surrounding ice and pavement to decrease while melting the ice and making roads safe!
This is very important to making homemade icecream. When salt is added to the ice the temperature of the whole system decreases enough to freeze the cream and make a tasty treat.
May 18, 1999Lance (Oregon, USA)Why does oil float on top of water when they are mixed?Try using our experiment with golf balls to find the answer!
May 10, 1999Cairn (England)What is the opposite to sublimation?Unlike freezing, whose opposite is melting, sublimation does not have an opposite. Simply, the term sublimation is used when ice turns to vapor or vapor turns to ice. Kind of tricky, huh? Find out more in our section on precipitation
May 7, 1999T. C. (Texas, USA)What makes water 'wet'??All liquids are considered wet, not just water. Something is wet because the molecular structure allows the molecules to flow past each other. This slippery feeling is what we call 'wet'. A gas acts the s ame way, except the molecules are too far apart to be wet. The molecules in a solid are packed too tightly for the molecules to slide. I guess you could say that water is wet because... it is!
April 7, 1999Meaghan (Massachusetts, USA)Why do colors fade in the Sun? Do some colors fade faster than others?The color objects appear depends upon their chemical makeup. Objects absorb some colors and reflect others. Some things, such as the ultraviolet rays in sun, can break the chemical bonds. This changes what is reflected back--when the object is bleached white, it reflects all the colors of light. Some objects fade faster simply because their chemical bonds break down faster.
February 2, 1999-- (Ohio, USA)What is the empirical formula for Lactic Acid?The molecular formula for Lactic Acid is C3H6O3. However, the empirical formula, which is defined as a formula showing the simplest composition rather than the number of molecules, is CH2O.
January 21, 1999Adam and Brice (Kentucky, USA)What does p.H. stand for?The 'p' is an operator symbol, which stands for 'negative logarithm'. The 'H' stands for 'Hydrogen'. So pH=-log{H+}. pH is a measure of the amount of hydrogen in a solution. It tells how acidic or alkaline the solution or water is. The ph scale goes from 0 to 14, where 7.0 is neutral. A pH of 0 to 7 is acidic, and 7 to 14 is alkaline.
November 19, 1998Candi (Kentucky, USA)If you add Flourine, Krypton, Polonium and Germanium together what do you get?Fluorine will react with all three, creating KrF2, PoF4, and GeF4. Don't try this at home!
January 19, 1998Christopher I know there is CO2 and CO, is there a CO3?There is a CO3 Christopher. It is has a -2 charge to it (chemists call any ion with a negative charge an anion). This CO3 ion (with a -2 charge) has a special name - it is called the carbonate ion.
January 14, 1998TW (South Dakota, USA)What happens if you burn a candle in outer space?The action of burning is a chemical reaction which requires oxygen. Since there is no oxygen in outer space, nothing can burn. The candle would never light.
December 2, 1997Kard How many elements are there? What is nuclear fusion?There are currently 112 elements in the periodic table.

Nuclear fusion is the process in which 2 atomic nuclei combine to form a heavier element. This type of reaction releases huge amounts of energy. The most common fusion reaction occurs on the Sun in which hydrogen atoms fuse to form helium. If scientists can figure out a safe and efficient way to carry out fusion reactions Earth, this would provide us a sustainable and clean source of energy for hundreds of years to come.

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