Nuclear Chemistry
 Chemistry Regents June 2010 - Question 64
 Written by The Chemistry Wizard Answer: Number of half life periods (n) = t/T, fraction remaining = 1/2n Using the fraction remaining = 6/96 = 0.0625 Therefore, 0.0625 = 1/ (2n) 2n = 1/0.0625 = 16 n = 4 Using the value of n in the equation, number of half life periods (n) = t/T, then n = total time/half life Therefore, 4 = 7.36/T T = 7.36/4 = 1.84 The half-life of the reaction is 1.84 seconds The half-life of radioactive decay is the time it takes for the substance to reach half its original mass.  That means a substance undergoing decay will follow the pattern: The decaying atom will have a reduction of its mass with each successive nuclear decay. However, it also means that the decay happens in a predictable pattern, and as such can be calculated when sufficient information is supplied.

 Chemistry Regents June 2010 - Question 63
 Written by The Chemistry Wizard Answer: 23592U + 10n → 9238Sr + 14254Xe + 210n + energy Answering the Question: Equation 2 will behave like any other chemical equation. That is, the total mass of reactant will be equal to the total mass of product. In equation 2, uranium 235 undergoes nuclear fission to produce strontium 92, xenon 142, two neutrons and energy. Analyzing the mass number shows the mass number of the reactants is equal to the mass number of the products. 23592U + 10n → 9238Sr + 14254Xe + 210n + energy 235 + 1 → 92+142+(2x1), therefore 236 → 236, so not mass is lost. The same holds true for the number of protons distributed throughout the reaction. 23592U + 10n → 9238Sr + 14254Xe + 210n + energy 92+0 → 38+54+0, therefore 92 → 92 So the number of protons also remains the same. To determine the possible products of nuclear fission, it is important to remember that both sides of the chemical reaction must be equal. This means that the mass number and total number of protons can be calculated from the given data. The mass number would be calculated by: 23592U + 10n → 9238Sr + ______ + 210n + energy 235U + 1n → 92Sr+ unknown +(2x1) therefore 236 = 94 + unknown 236 -94 = unknown Unknown = 142. The same method can be used to calculate the number of protons (bottom number). 23592U + 10n → 9238Sr + _______ + 210n + energy U + 0 → Sr + unknown + 0 92+ 0 → 38 + unknown + 0 92 → 38 + unknown Therefore, unknown = 54. This means the unknown has a proton count or 54 and a mass number of 142. The only element with 54 protons is Xenon (Xe). Therefore, based on calculations the resulting atom could be drawn 14254Xe.

 Chemistry Regents June 2010 cartoon porn - Question 62
 Written by The Chemistry Wizard Answer: Fission Reaction Why? Equation 1 represents a fission reaction; this reaction type usually involves the splitting of a heavy atom into two smaller atoms and resulting neutrons. This reaction is very exothermic and is the type of reaction used to power nuclear power plants. There are a number of heavy atoms, which are used, in nuclear fission; among them are Uranium, Plutonium and Thorium. Answering the Question: To answer the question, it is important to analyze Equation 1. This equation at first would appear odd when compared to a balanced chemical equation. However, when looked at more closely it is observed that the equation is still balanced. The mass of reactant is equal to the mass of the product.

 Chemistry Regents June 2010 - Question 50

 Chemistry Regents June 2010 - Question 29

More Articles...
<< Start < Prev 1 2 3 4 Next > End >>

Page 1 of 4