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# how to find decay factor

Question:Find the percent of decrease for each decay factor for the following examples 1) 0.92 2) 0.65 3) 0.04 4) 0.995 5) 0.73 6) 0.18 7) 0.65 8) 0.025 Use a table to graph each function 1) y=18*0.98^x 2) y=36* (1/3)^x Please help me, i have been searching the internet for help, i forgot my text book in class and cant afford to lose points for not handing in my homework, all help will be appreciated<3

Answers:Your first question is unclear, but I think this is what you want. 1) % decrease = 1 - N * 100% % de. = 1 - (0 92) * 100% % de. = 0 08 * 100% % de. = 8% 2) % decrease = 1 - N * 100% % de. = 1 - (0 65) * 100% % de. = 0 35 * 100% % de. = 35% Do the rest in a similar way. Take a range of values for x, and work out the values for y. Plot the points and draw your curve. 1) When x = -2; y = 18 * 0 98^x y = 18 * 0 98^- y = 18 * 1 04 123 282... y = 18 742 19... Pt.(-2, 18 74..) When x = -1; y = 18 * 0 98^x y = 18 * 0 98^-1 y = 18 * 1 02 0408... y = 18 367 346... Pt.(-1, 18 367..) When x = 0; y = 18 * 0 98^x y = 18 * 0 98^ y = 18 * 1 y = 18 Pt.(0, 18) When x = 1; y = 18 * 0 98^x y = 18 * 0 98^1 y = 18 * 0 98 y = 17 64 Pt.(1, 17 64) When x = 2; y = 18 * 0 986^x y = 18 * 0 98 y = 18 * 0 9604 y = 17 2872 Pt.(2, 17 2872) Now plot the points onto the graph. Do likewise with the next question.

Question:Complete the table for the radioactive isotope. (Round to 2 decimal places.) Isotope 226Ra Half-life (Years) 1599 Initial Quantity _____ Amount after 1000 years .40 grams The answer is .62 grams, I just need to know how to get there. Thanks! Oh, and by the way, in 226Ra the 226 is supposed to be superscript (at least I think that's the word).

Answers:B = A(0.5)^(t/half life) 0.40 = A(0.5)^(1000/1599) 0.40 = A(0.5)^0.625391 0.40 = A(0.648244) A = 0.4/0.648244 = 0.6171 grams 226Ra

Question:Plutonium is red-hot as it decays and apparently gives off a lot of heat. However, I cannot find a temperature. Is the temperature always a certain level or is it hotter at first, then cooling off as it decays?

Answers:Plutonium 238 is the isotope used to fuel spacecraft. It has a half life of about 88 years meaning that if you have 1 gram of it now, in 88 years you will have 1/2 gram of it. The heat is used to power a thermocouple and that makes electricity. Thess links are pretty good reading: http://www.epa.gov/radiation/radionuclides/plutonium.htm http://www.lanl.gov/source/orgs/nmt/nmtdo/AQarchive/05spring/heart.html http://www.uic.com.au/nip18.htm Remember, heat and temperature are too different things. The environment where the stuff is kept would determine the temperature. How much of it you have would determine the amount of heat it outputs. I would surmise that over a period of 88 years, the heat output would be 1/2 of what it originally was.

Question:how do you find factors of large numbers which will be the sum or difference of another number? Example: what are the factors of 4860 when added together will be the sum of -63? I mean, how would you know where to start cuz the number is large. If i would do trial and error with numbers it takes a really long time. Please help.

Answers:if the number is even then its divisible by 2. if the sum of the num is divisible by 3, then the num is divisible by 3. if the last two digits of a number is divisible by 4, then the num is divisible by 4, if the num ends in 0 or 5 its divisible by 5 and so on...