# Questions Asked in December 2012

## Most Popular Questions of December 2012

1. ### Msth

olve each inequality. 1. m – 7 < 6 (1 point) m < –1 m > 1 m < 13 m < –13 2. y + 5 ≥ 7 (1 point) y ≤ 2 y ≤ 12 y ≥ 2 y ≥ 12 3. p + 12 > 9 (1 point) p > 21 p > 3 p > –21 p > –3 4. Translate the following statement into an inequality: Five

asked by Lauran on December 12, 2012
2. ### MATH

1. Terre Haute to Indianapolis to Bloomington measures 3 cm on the map. What is the actual distance? 100 km 150 km 200 km 250 km 2. Fort Wayne to Richmond to New Albany measures 6 cm on the map. What is the actual distance? (1 point) 300 km 250 km 350 km

3. ### geometry

In the middle of the page, draw an equilateral triangle with 2 inch sides and the bottom parallel to the bottom of the page. 2. From the center of the right side, draw two parallel lines an inch apart and an inch long. 3. Draw a line from the end of one of

asked by Des on December 10, 2012

1. 7r – 7 = 2r + 18 (1 point) r = –5 r = 5 r = 2.2 r = 1.2 2. 2x + 12 = 18 – x (1 point) x = 3 x = 10 x = 6 x = 2 3. 8x – 3 = 15x + 18 (1 point) x = –3 x = 3 x = 2.1 x = .9 4. 6y – 6 = 4y + 16 (1 point) y = 2.2 y = –2.2 y = 11 y = 5 5. 3(x

asked by Delilah on December 13, 2012
5. ### English

Identify the structure used in each of the sentences below. 1. The hamburger came from Hamburg, Germany, and the hot dog came from Frankfurt. simple compound complex compound-complex 2. The idea of placing meat on a bun, however, came from the United

asked by Fate on December 28, 2012
6. ### english

Shortly before the Russian Revolution, an eccentric man named Rasputin became ______as the "mad monk." Because he dressed like a peasant, drank heavily, and rarely bathed, the nobility often felt ____during their encounters” with him at the palace. Yet

7. ### math stuff

how do u find the unit rate of a question

asked by sk8rboi on December 3, 2012
8. ### algebra

using substitution how to solve x + 4y = 8 2x + 5y = 29

asked by noah on December 3, 2012
9. ### central middle

what do you get as your new length and width if you enlarge a 8 cm by 10 cm photo by a scale factor of 150%

asked by Anonymous on December 3, 2012
10. ### Math

1. Given a scale factor of 2, find the coordinates for the dilation of the line segment with endpoints (–1, 2) and (3, –3). (2, 4) and (6, 6) (2, 4) and (6, 6) (–2, 4) and (6, –6) (2, –1) and (–3, 3) 2. Given a scale factor of one-half , find

asked by Briana T on December 6, 2012
11. ### English

chapter 14 sentence check 2... Although everything about the Nazis ﬁlled the Dutch spy with ____ (convert), his assignment was to ___(convert)peoples pain.

asked by Sam on December 3, 2012
12. ### math

What is the ratio of 4/5 to 7/15?

asked by me on December 3, 2012
13. ### Physics

A block slides from rest with negligible friction down a track, descending 5.0m to point P at the bottom. It then slides on the horizontal surface. The coefficient of friction between the block and the horizontal surface is 0.20. How far does the block

asked by Anonymous on December 29, 2012
14. ### Physics

As a box is pushed 30 meters across a horizontal floor by a constant horizontal force of 25 newtons, the kinetic energy of the box increases by 300 joules. How much total internal energy is produced during this process?

asked by Shannon on December 9, 2012
15. ### Geometry

ABCD is a rhombus. Explain why triangle ABC is congruent to triangle CDA.

asked by BaileyBubble on December 14, 2012

1. Write the fraction eight-ninths as a percent. Round to the nearest hundredth of a percent where necessary. (1 point) 88.89% 1.13% 44.44% 66.67% 2. Write the decimal 0.041 as a percent. (1 point) 41% 4.1% 410% 0.41% 3. A study in your town found that 54

asked by Delilah on December 5, 2012
17. ### algebra

what is the simpliest form of the equation 3 sqrt 750 + 3 sqrt 2058 - 3 sqrt 48 possible answers 14 3sqrt6 17.5 3sqrt6 33 3sqrt6 10 3sqrt6

asked by lee on December 2, 2012

Tom buys a shirt for $22.00 plus 7% sales tax. His cousin buys a shirt for$18.00 plus 4% sales tax. a. How much do Tom and his cousin pay for the shirts? Show your work. b. Who spent more on tax? (3 points) Is my answer correct: B: Tom's cousin **I

asked by Delilah on December 5, 2012
19. ### Physic

1. Water at a pressure of 3.00 x 10 5th Pa flows through a horizontal pipe at a speed of 1.00 m/s. The pipe narrows to one-fourth its original diameter. What is the speed of the flow in the narrow section? Not sure was successfully posted

asked by Leo on December 5, 2012
20. ### Chemistry

Classify each of the following as a redox reaction or a non-redox reaction. Zn+CuCl2 -> ZnCl2+Cu HCl+NaOH -> H2O+NaCl 2CO+O2 -> 2CO2 SO3+H2O -> H2SO4

asked by Anon on December 2, 2012
21. ### Chemistry 3A

a titration required 18.38mL of 0.1574 M NaOH solution. how many moles of NaOH were in this volume?

asked by Gurjot on December 6, 2012
22. ### 7th grade math help Ms. Sue

3. Which of the following equations has an infinite number of solutions? (1 point) 3x – 3 = –4x 2y + 4 – y = 16 7x + 5 = 4x + 5 + 3x 6y – 2 = 2(y – 1) 5. Write an inequality for the word sentence: k is less than zero. (1 point) k > 0 k ≥ 0 k <

asked by Delilah on December 18, 2012
23. ### ENGLISH

Many people are surprised to learn how __1__ poverty is __2__ America. Today millions live below the poverty line, and the number seems to escalate daily. Judy and Martin Reed exemplify the old saying, “Opposites attract.” A __3__ Judy chooses work

asked by margaret on December 6, 2012
24. ### physics

Water falls from a height of 84 m. Assuming that all the energy is converted into heat, the rise in temperature of water will be (4200 J/(kg °C) and g=10 m/s2)?

asked by Salem on December 4, 2012

asked by BaileyBubble on December 12, 2012
26. ### math

The ladders shown below are standing against the wall at the same angle. How high up the wall does the longer ladder go? (All measurements are in feet.) ladders 11.25 ft 12.5 ft 14 ft 14 ft 2. The pair of polygons is similar. Find the value of x. polygons

asked by Steve Plzzz Help now !! on December 3, 2012
27. ### GEOMETRY

In triangle ABC, centroid D is on the median line segment AM. AD=x+4 and DM=2x-4. Find AM.

asked by Anonymous on December 6, 2012
28. ### Chemistry

Use the data given below to construct a Born - Haber cycle to determine the electron affinity of Br? DH°(kJ) K(s) → K(g) 89 K(g) → K⁺(g) + e⁻ 419 Br2(l) → 2 Br(g) 193 K(s) + 1/2 Br2(g) → KBr (s) -394 KBr(s) → K⁺(g) + Br⁻(g) 674 I know

asked by Rob on December 8, 2012
29. ### I don't understand this chemistry problem?

The question reads: Place the following elements in order of decreasing atomic size: selenium, chlorine, fluorine, rubidium, calcium, and sulfur. I looked this up on a periodic table and my answer was: Rb, Se, Ca, Cl, F, S. This is still marked wrong, and

asked by Amy on December 3, 2012

1. y minus five over three= 1 (1 point) –2 8 18 6 2. 6x + 29 = 5 (1 point) –4 –18 204 –144 3. Combine like terms: –21a + 16a (1 point) –5a 5a 37a –37a Simplify the expression. 4. 9a – b – 2a – 10b (1 point) –7a + 11b 11a + 9b –11a

asked by Delilah on December 11, 2012
31. ### Chemistry

On another planet, the isotopes of titanium have the following natural abundances. Isotope 46Ti Abundance 70.900% Mass(amu) 45.95263 Isotope 48Ti Abundance 10.000% Mass(amu) 47.94795 Isotope 50Ti Abundance 19.100% Mass(amu) 49.94479 What is the average

asked by Anon on December 8, 2012

Three objects are moving along a straight line as shown in the figure. Taking the positive direction to be to the right, what is the total momentum of this system? Pos ---> 5.00 m/s, 8.00 kg Neg 2.00 m/s, 3.00 kg A) -14 kg m/s B) +106 kg m/s C) +14 kg m/s

asked by Anonymous on December 6, 2012
33. ### Chemistry

Balance the following equation for a half reaction that occurs in acidic solution. Use e– as the symbol for an electron. Mo^3+ -> MoO2^2+ Is the answer 2O+2Mo^3+ -> MOO2^2++3e^-?

asked by Anonymous on December 3, 2012
34. ### 7th grade math Ms. Sue last two questions thanks

15. In Store A, a book that regularly sells for $24.99 is on sale at 15% off. In Store B, the same book regularly sells for$27.99 and is on sale at 25% off. Which store sells the book for the lower sale price? (1 point) Store A; Store A’s sale price is

asked by Delilah on December 5, 2012
35. ### Economics

PROBLEM SOLVING 1: "ANDREA'S SOFTWARE BUSINESS" I. Complete the following table: DO THE MATH Data Number of Programs Total Fixed Costs Total Variable Costs Total Costs Marginal Costs Average Fixed Costs Average Variable Costs Average Total Costs 0 $60$0

asked by Timithy on December 4, 2012
36. ### chemistry 122

81) According to the following thermochemical equation, what mass of HF (in g) must react in order to produce 345 kJ of energy? Assume excess SiO2. SiO2(s) + 4 HF(g) �� SiF4(g) + 2 H2O(l) DH°rxn = -184 kJ 81) A) 173 g B) 37.5 g C) 150. g D)

asked by sean on December 11, 2012
37. ### Geometry

Find the values of the variables and the lengths of the sides of this kite. Side A=y-4, side B=x+5,side C= x+12, side D= 2x+5

asked by BaileyBubble on December 14, 2012
38. ### science

Calculate the density of sulfur hexafluoride gas at 703 torr and 23°C. density is mass/volume so how do i get those from what i am given? also ) Calculate the molar mass of a vapor that has a density of 6.735 g/L at 11°C and 743 torr.

asked by Samantha on December 15, 2012
39. ### Physics

a 32 kg child stands at the edge of a circular platform that rotates at w=2rad/s about its center. Mass of platform=60kg, radius=2m. The child walks from the rim towards the center. Find the Angular speed when the child reaches a point 0.500 m from the

asked by Help! on December 14, 2012
40. ### Math

Tom buys a shirt for $22.00 plus 7% sales tax. His cousin buys a shirt for$18.00 plus 4% sales tax. a. How much do Tom and his cousin pay for the shirts? Show your work. b. Who spent more on tax? Please Help Me!!

asked by X( on December 27, 2012
41. ### chemistry

How would the 2s and 3p orbitals differ from the 1s and 2p orbitals? Check all that apply. possible answers The and orbitals would have more nodes than and orbitals. The orbital would be the same shape as the orbital but would be smaller in size. The and

asked by kdb on December 1, 2012
42. ### Physics

Two coupled boxcars are rolling along at 4.0 when they collide with and couple to a third, stationary boxcar. 1.) What is the final speed of the three coupled boxcars? 2.) What fraction of the cars' initial kinetic energy is transformed into thermal

asked by Amy on December 2, 2012
43. ### Margaret

____1__ young people may be able to list the many accomplishments of the Reverend Dr. Marting Luther, King jr. They may know that he was a civil rights leader who aspired to achieve racial harmony and was an __2__ of peaceful but direct action. They may

asked by english on December 8, 2012
44. ### Geometry- Preferably Ms. Sue

Lucinda wants to build a square sandbox, but she has no way of measuring angles. Which of the following explains how she can make sure the sandbox is square by measuring only length? A)Arrange four equal-length sides, so the diagonals bisect each other.

asked by BaileyBubble on December 13, 2012
45. ### math

A school has 63 students studying Physics, Chemistry and Biology. 33 study Physics, 25 Chemistry and 26 Biology. 10 study Physics and Chemistry, 9 study Biology and Chemistry while 8 study both Physics and Biology. Equal numbers study all three subjects as

asked by ifi on December 24, 2012
46. ### Physics

Glycerin is poured into an open U-shaped tube until the height in both sides is 20 {\rm cm}. Ethyl alcohol is then poured into one arm until the height of the alcohol column is 20 {\rm cm}. The two liquids do not mix. What is the difference in height

asked by Amanda on December 7, 2012

1. 3w – 10w (1 point) 13w –7w –7 7w 2. y + 1.2y +1.2z (1 point) 2.4yz 1.3y + 1.2z 1.2y2 + 1.2z 2.2y + 1.2z 3. 6r + r – 5r (1 point) 2r 1r + r 0r 7r – 5r 4. 5x + 2(x + 6) (1 point) 7x + 6 7x^2 + 12 7x + 12 7x (x + 6) 5. –3m + 3(m + 6) (1 point)

asked by Delilah on December 7, 2012
48. ### Physics

Two 0.4 kg soccer balls collide elastically in a head-on collision. The first ball starts at rest, and the second ball has a speed of 3.5 m/s. After the collision, the second ball is at rest. A.) What is the final speed of the ball? B.) What is the kinetic

asked by Ana on December 17, 2012

18. In 2000, the circulation of a local newspaper was 3,250. In 2001, its circulation was 3,640. In 2002, the circulation was 4,100. a. Find the percent of increase in the newspaper’s circulation from 2000 to 2001 and from 2001 to 2002. b. Which period

asked by Delilah on December 5, 2012
50. ### CHEMISTRY HELP ASAP

A 1.26 g sample of He gas has a pressure of 0.123 atm and a volume of 32.6 L. What is the temperature of the sample, in °C?

asked by Linda on December 19, 2012
51. ### geometry

The Polygon Angle-Sum Theorem states the following: The sum of the measures of the angles of an n-gon is ____. (1 point) (n – 1)180o (n – 2)180o 9. What is the measure of one angle in a regular 16-gon? (1 point) 2,520o 202.5o 157.5o 78.75o 10. The

asked by josh on December 31, 2012
52. ### Science

Based on the following information: A series of chemicals were added to some AgNO3(aq). NaCl(aq) was added first to the silver nitrate solution with the end result shown below in test tube 1, NH3(aq) was then added with the end result shown in test tube 2,

asked by Spoa on December 2, 2012
53. ### Consumer math

Complete the chart to find the mean, variance and standard deviation. Remember to use commas and round numbers to the nearest tenth. X _ X _ X - X _ (X - X)2 1. 900 = 466.2 = The mean is 2. 35 = -398.8 = 159,041.4 The median is 3. 500 = 66.2 = The variance

asked by yamilex on December 11, 2012

16. Find the final balance in an account with $730 invested at 3% annual simple interest for 4 years. (1 point)$735.48 $87.60$817.60 $8,760.00 is the answer 817.60 asked by Delilah on December 5, 2012 55. ### math A 154-lb person burns 420 calories per hour riding an exercise bicycle at a rate of 15 mi/h. Write a function rule to represent the total calories burned over time by that person. Explain how the information in the problem relates to the function. Thank asked by Christine on December 8, 2012 56. ### physics the velocity of sound in air 27 C is 340m/s calculate velocity of sound in air at 127 C asked by pramila on December 25, 2012 57. ### Physics Five Forces act on an object: 1. 60 N at 90 degrees 2. 40 N at 0 degrees 3. 80 N at 270 degrees 4. 40 N at 180 degrees 5. 50 N at 60 degrees What are the magnitude and direction of a sixth force that would produce equilibrium? asked by Michael on December 8, 2012 58. ### Calculus Help!! Region R is bounded by the functions f(x) = 2(x-4) + pi, g(x) = cos^-1(x/2 - 3), and the x axis. a. What is the area of the region R? b. Find the volume of the solid generated when region R is rotated about the x axis. c. Find all values c for f(x) and asked by Anonymous on December 21, 2012 59. ### maths --plse help me.. how to find the square root of 404.41 with steps please help asked by sapna on December 18, 2012 60. ### help hexagon geometry A regular hexagon is inscribed in a circle and another regular hexagon is circumscribed about the same circle. What is the ratio of the area of the larger hexagon to the area of the smaller hexagon? Express your answer as a common fraction. How is this asked by Knights on December 19, 2012 61. ### GEOMETRY HELP ASAP!!!! what are the missing reasons in the 2 column proof? Given: JM = ML and m m KL Statements Reasons 1. JM = ML 1. Given 2. KM = KM 2. ? 3. m m KL 4. ? I think 2 is reflection but im not positive. and I have no clue about 4. asked by Anonymous on December 7, 2012 62. ### algebra suppose you want to build a rectangular sandbox where the width is 4 ft less than the length and the diagonal is 4 ft longer than the length. what are the dimensions asked by carlos on December 1, 2012 63. ### Physics Water flows at 0.25L/s through a 9.0-m-long garden hose 2.0cm in diameter that is lying flat on the ground.The temperature of the water is 20degC. What is the gauge pressure of the water where it enters the hose? in Pa asked by Cassie on December 5, 2012 64. ### maths the 8th term of an a.p is 37 and 12th term is 57 .find the a.p please help this questions .please help. asked by simranpreet on December 3, 2012 65. ### maths A rectangular grassyplot is 112m long and 78m broad. It has a gravel path 2.5m wide all around it on the inside. Find the area of path and the cost of constructing it at the rate of 1.80 per sq. m . asked by Anonymous on December 28, 2012 66. ### math Tomas needs to cut a piece of wood for a model airplane he is building. He has four pieces of wood: 5 feet, 4 feet, 6 feet, and 3 feet long. If the length of wood he needs to cut is 11 square root feet long, which piece of wood should he cut to have the asked by Anonymous on December 12, 2012 67. ### Biology Suppose you are a scientist trying to help people who cannot produce an enzyme needed for proper digestion. How could you use genetic engineering techniques to make transformed bacteria that produce the enzyme? asked by BaileyBubble on December 17, 2012 68. ### chemistry How much 10.0 M HNO3 must be added to 1.00 L of a buffer that is 0.0100 M acetic acid and 0.100 M sodium acetate to reduce the pH to 5.00? pKa of acetic acid= 4.75 asked by Victoria on December 7, 2012 69. ### Physics- Someone Please Help!!! A 60.00 cm guitar string under a tension of 46.000 N has a mass per unit length of 0.11000 g/ cm. (a) What is the speed of the wave? (b) What is the fundamental wavelength for this string? (c) What is the fundamental frequency for this string? (d)What is asked by Megan on December 3, 2012 70. ### Algebra 2. Please help ASAP The pH of a liquid is a measure of how acidic or basic it is. The concentration of hydrogen ions in a liquid is labeled [H+]. Use the formula pH = –log[H+] to find the pH level, to the nearest tenth, of a liquid with [H+] about 5.4 x 10–14. A. 14.7 B. asked by Tori on December 14, 2012 71. ### Chemistry A sample of 40.0 mL of hydrogen is collected by water displacement at a temperature of 20 degrees Celcius. The barometer reads 751 torr. What is the volume of the hydrogen at STP (standard temperature and pressure)? asked by Kia on December 16, 2012 72. ### maths the sum of first 8 terms of an arithmetic progression is 156.the ratio of its 12th term to its 68th term is 1:5.calculate the first term and the fifteenth term. please help this questions please. asked by simranpreet on December 3, 2012 73. ### Physics- PLEASE HELP Two pipes of equal length are each open at one end. Each has a fundamental frequency of 715 Hz at 300 K. In one pipe the air temperature is increased to 313 K. If the two pipes are sounded together, what beat frequency results? asked by Tia on December 5, 2012 74. ### chemistry What volume in mL of 0.0985 M sodium hydroxide solution is required to reach the equivalence point in the complete titration of a 15 mL sample of 0.124 M phosphoric acid? asked by What? on December 10, 2012 75. ### Chemistry - Photons Water is exposed to infrared radiation of wavelength 2.5×10−4 cm. Assume that all the radiation is absorbed and converted to heat. How many photons will be required to raise the temperature of 2.5 g of water by 2.5 K? -------------------------- I tried asked by Amy on December 7, 2012 76. ### Chemistry To treat a burn on your hand, you decide to place an ice cube on the burned skin. The mass of the ice cube is 16.0 g, and its initial temperature is -11.4 °C. The water resulting from the melted ice reaches the temperature of your skin, 31.0 °C. How much asked by Anon on December 8, 2012 77. ### Chemistry The figure below is a heat curve for an unknown outerspace substance discovered by the Mars rover. By understanding the heat curve, scientists can make inferences about the composition of the planet. What is the temperature of fusion, Tfusion, and asked by Anon on December 9, 2012 78. ### Chemistry determine the pH of a 0.116 M Ba(OH)2 solution at 25 degrees C. i keep getting 13.06 for this answer, but the answer is 13.37 :S what i do is i take the negative log of the concentration which is 0.9355 which is pOH. i know that pH = 14 - pOH so i get pH = asked by Anya on December 13, 2012 79. ### Physics A 50 kg skater at rest on a frictionless rink throws a 2 kg ball, giving the ball a velocity of 10 m/s. Which statement describes the skaters subsequent motion? Explain please. a. 0.4 m/s in the same direction as the ball. b. 0.4 m/s in the opposite asked by Alexa on December 2, 2012 80. ### english Identify what is wrong with each italicized pronoun reference. If the driver hits another car in a moving violation, the cost of your insurance will go up. indefinite pronoun ambiguous reference no specific antecedent asked by yamilex on December 14, 2012 81. ### AP physics B A phone cord is 3.26 m long. The cord has a mass of 0.224 kg. A transverse wave pulse is produced by plucking one end of the taut cord. The pulse makes four trips down and back along the cord in 0.865 s. What is the tension in the cord? Answer in units of asked by Cold Turkey on December 5, 2012 82. ### 8th grade math for Ms. Sue please check How is an inequality different from an equation? Give a real-world scenario in which you would write an inequality rather than an equation. Daphne has$25. She wants to buy two new paint brushes for her art teacher. Daphne needs to know the average price

asked by Destiny on December 27, 2012
83. ### physics

the muzzle velocity of a 50.0g shell leaving a 3.00kg rifle is 400 m/s what is the recoil velocity of the rifle

asked by alyssa on December 16, 2012
84. ### Physics

A bead slides without friction around a loop- the-loop. The bead is released from a height of 12.9 m from the bottom of the loop-the- loop which has a radius 4 m. The acceleration of gravity is 9.8 m/s2 . A 4m 12.9 m What is its speed at point A ? Answer

asked by Richard on December 14, 2012
85. ### Math-trig

A stairway runs up the edge of the pyramid. From bottom to top the stairway is 92 m long. The stairway makes an angle of 70° to the base edge, as shown. A line from the middle of one of the base edges to the top of the pyramid makes an angle of elevation

asked by Anonymous on December 19, 2012

11. The sales tax rate is 6.9%. a. Find the tax paid for a pair of boots with a list price of $128. b. What is the total cost of the pair of boots? (1 point)$8.83; $128.88$8.83; $136.83$0.88; $136.83$0.88; $128.88 12. Doug is a salesperson in a retail asked by Delilah on December 5, 2012 87. ### 7th grade Social Studies Ms. Sue 1. Which climate region dominates most of Northern Africa? (1 point) humid continental highland tundra arid 2. What kind of storm covers the largest area? (1 point) rainstorm blizzard hurricane tornado 3. Earth’s climate is affected by latitude, asked by Delilah on December 3, 2012 88. ### Chemistry When 0.40 g of impure zinc reacted with an excess of hydrochloric acid, 127 mL of hydrogen was collected over water at 10 degress C The external pressure was 737.7 Torr. a) What volume would the dry hydrogen occupy at 1.00 atm and 298 K ? b) What amount asked by Sandy on December 13, 2012 89. ### Algebra In 1915, the tallest flagpole in the world was in San Francisco. a. When the angle of elevation of the sun was 55 degrees, the length of the shadow cast by this flagpole was 210 ft. Find the height of the flagpole to the nearest foot. b. What was the asked by Lavanda on December 19, 2012 90. ### Chemistry The complex ion, [Ni(NH3)6]2+, has a maximum absorption near 580 nm. Calculate the crystal field splitting energy (in kJ/mol) for this ion. asked by Emma on December 6, 2012 91. ### Business Math Being inventory of 12 sets of paints at a cost of$1.50 each. During the year the store purchased 4 sets at $1.60, 6 sets at$2.20, 6 sets at $2.50, and 10 sets at$3.00. By the end of the year, 25 sets were sold. Caculate the number of paint sets in stock

asked by Jean on December 26, 2012
92. ### chemistry

Instant cold packs, often used to ice athletic injuries on the field, contain ammonium nitrate and water separated by a thin plastic divider. When the divider is broken, the ammonium nitrate dissolves according to the following endothermic reaction:

asked by savannah on December 19, 2012
93. ### chemistry

A magic number is the name given to certain numbers of protons or neutrons that have a high correlation to stability in nuclei. Magic # of protons: 2,8,20,28,50,82 Magic # of neutrons: 2,8,20,38,50,82,126, 184 Using general trends, predict the stability of

asked by michelle on December 4, 2012
94. ### Physics

The period of motion of an object-spring system is T = 0.474 s when an object of mass m = 296 g is attached to the spring. (a) Find the frequency of motion in hertz. _______Hz (b) Find the force constant of the spring. _______N/m (c) If the total energy of

asked by Ame on December 6, 2012
95. ### chemistry 100

How do I disassociate Li2CO3 I have tried Li_2CO_3--> 2Li^+ + 3CO^2- What am I doing wrong?

asked by Anita on December 13, 2012

Converting sunlight to electricity with solar cells has an efficiency of 15%. It's possible to achieve a higher efficiency (though currently at higher cost) by using concentrated sunlight as the hot reservoir of a heat engine. Each dish in the figure

asked by Anonymous on December 4, 2012
97. ### Math Help PLease Fast!!!!!!!!!!!!!!

Graph the system of inequalities. Then use your graph to identify the point that represents a solution to the system. x > ¨C2 y ¡Ü 2x + 7 A. (¨C1, 6) B. (1, 11) C. (¨C1, 4) D. (¨C3, ¨C1)

asked by Lola on December 12, 2012
98. ### Chemistry

Write a balance equation for the reaction of nitric acid (HNO3) with each base solution : . NaHCO3, . MgCO3. ( Please include the phases of the substance)

asked by Jennifer on December 8, 2012
99. ### algebra

For the function f(x)=(7-8x)^2, find f^-1. Determine whether f^-1 is a function.

asked by lee on December 10, 2012
100. ### Math help ? confused

The length of the Boston Marathon is 138,435 ft. Each stride, or step, by a particular runner is 3 ft long. Does the number of strides the runner takes fit evenly into the length of the race? I am lost on this question. Can anyone give me a direction? Do I

asked by Tobi on December 5, 2012