Most popular questions and responses by bill
  1. Chemistry

    Metals lose electrons under certain conditions to attain a noble-gas electron configuration. How many electrons must be lost by the element Ca? Is it 2 e^-? Which noble-gas electron configuration is attained in this process? argon radon krypton xenon

    asked on October 28, 2012
  2. algebra

    Are the following true or false? 1. The difference of two natural numbers is always a natural number. 2. The sum of two natural numbers is always a natural number. 3. The quotient of two natural numbers is always a natural number. 4. The difference of two

    asked on September 7, 2010
  3. Chemestry

    Iron metal reacts with oxygen gas to form rust, iron (III) oxide. Which of the following correctly shows the balanced equation for this reaction?

    asked on December 2, 2015
  4. Chemistry

    What quantum numbers specify these subshells? 2s n= l= 3p n= t= 6d n= l=

    asked on October 28, 2012
  5. microeconomics

    The cost of producing flat-screen TVs has fallen over the past decade. Let’s consider some implications of this fact. A.) Draw a supply-and-demand diagram to show the effect of fallen production costs on the price and quantity of flat-screen TVs sold.

    asked on June 9, 2013
  6. social studies

    Which theory do most scientists believe about the first inhabitants of North America? A. They walked across the frozen Bering Land Bridge. B. They swam across the Pacific Ocean. C. They sailed across the Atlantic Ocean.---------- D. They walked across the

    asked on August 28, 2018
  7. AP Chem

    At a particular temperature, Kp = 0.25 for the following reaction. N2O4(g) 2 NO2(g) (a) A flask containing only N2O4 at an initial pressure of 5.3 atm is allowed to reach equilibrium. Calculate the equilibrium partial pressures of the gases. (b) A flask

    asked on January 8, 2012
  8. PreCalculus

    "A kite is flying 100ft off the ground, and its line is pulled taut. The angle of elevation of the kite is 43 degrees. Find the length of the line."

    asked on March 23, 2011
  9. chemistry

    What has the higher normal melting point: CHI3 or CHF3? The answer in the book is CHI3. So I'm assuming the answer is CHI3 because Iodine is the bigger and will form larger london dispersion forces, but isn't a stronger dipole moment formed in CHF3 because

    asked on January 16, 2013
  10. math

    In an elevator, you go up 3 floors and down 4 floors. Write an integer that represents the net change in your position.

    asked on January 25, 2018
  11. Chemistry

    A 5.00-g sample of aluminum pellets (specific heat capacity = 0.89 J/°C · g) and a 10.00-g sample of iron pellets (specific heat capacity = 0.45 J/°C · g) are heated to 100.0°C. The mixture of hot iron and aluminum is then dropped into 91.9 g of water

    asked on November 13, 2011
  12. World History

    Analyze the ways in which interdependence has affected both developed and developing nations. In your answer, be sure to use examples and evidence to explain the benefits and risks facing each type of nation. In your analysis, evaluate a problem that

    asked on April 13, 2019
  13. chemistry

    What mass of F2 is needed to produce 116 g of PF3 if the reaction has a 77.4% yield?

    asked on March 10, 2013
  14. physics

    A rocket blasts off from rest and attains a speed of 49 m/s in 16 s. An astronaut has a mass of 56.3 kg. What is the astronaut's apparent weight during take off?

    asked on February 8, 2016
  15. Chemistry

    At a certain temperature and pressure, one liter of CO2 gas weighs 1.45 g. What is the mass of one liter of C4H10 gas at the same temperature and pressure?

    asked on October 16, 2012
  16. physics

    A fire engine must lift 30 kg of water a vertical distance of 20 m each second. What is the amount of power needed for the water pump for this fire hose? P=W/t=Fd/t=mgd/t (30)(9.8)(20)/1= 5880 W is that right?

    asked on January 20, 2015
  17. Chemistry (Titrations)

    In order to standardize a KMnO4 solution, 0.2848 g Fe(NH4)2(SO4)2·6H2O was dissolved in 25 mL 0.18 M H2SO4. The KMnO4 solution was added to the Fe(NH4)2(SO4)2·6H2O solution until a pale pink color persisted. The titration took 24.2 mL of KMnO4 solution.

    asked on November 30, 2014
  18. AP Chem

    At a particular temperature, K = 1.00 102 for the following reaction. H2(g) + I2(g) 2 HI(g) In an experiment, 1.23 mol H2, 1.23 mol I2, and 1.23 mol HI are introduced into a 1.00 L container. Calculate the concentrations of all species when equilibrium is

    asked on January 8, 2012
  19. Biology

    What are the roles of hydrogen peroxide, oxygen, hydrogen, and catalase in the following chemical reaction? catalase 2H2O2 > O2 + 2H2O A. Catalase is an enzyme, O2 and H2O are substrates, and H2O2 is a reactant. B. Catalase is a substrate, O2 and H2O are

    asked on September 12, 2017

    Which section of a personal narrative requires the most development? a. introduction b. conclusion c. character introduction d. plot

    asked on October 5, 2015
  21. Chemistry

    What is the approximate ratio of the solubility of CaSO4 (Ksp = 2.4 x 10−5) in pure water to the solubility of CaSO4 in 0.10 M Na2SO4 at the same temperature?

    asked on February 27, 2017
  22. calc

    Show that the equation x^3-15x+c=0 has at most one root in the interval [-2,2].

    asked on February 28, 2011
  23. bio

    In humans, the ABO blood type is under the control of autosomal multiple alleles. Red-green color blindness is a recessive X-linked trait. If two parents who are both type A and have normal vision produce a son who is color-blind and type O, what is the

    asked on November 13, 2008
  24. english

    need help with this Nominative Absolutes sentence "The town held a festival because the harvest had been so large.". is this right? The town held a festival the harvest been so large.

    asked on April 11, 2011
  25. Chemistry

    A hot air balloon is filled with 1.39 × 106 L of an ideal gas on a cool morning (11 °C). The air is heated to 105 °C. What is the volume of the air in the balloon after it is heated? Assume that none of the gas escapes from the balloon.

    asked on October 16, 2012
  26. english-german

    hello! i need to give a thirty minutes lectore to children(age 11-12).My topic is travelling.What can i do?Do you have any exanples of any games i can make to make it interesting?They can also act and learn some vocabulary but mostly they need to do

    asked on November 15, 2008
  27. physics

    A supertanker (mass = 1.57E+8 kg) is moving with a constant velocity. Its engines generate a forward thrust of 7.47E+5 N. Determine the magnitude of the resistive force exerted on the tanker by the water. 7.47×10^N is correct, but I need to know how

    asked on December 6, 2017
  28. Binomial Probability

    Before 1918, wolves were shown as 55% male, 45% female. From 1918 to present they were shown as 70% male and 30% female. In a random sample of 12 wolves, what was the probability that 6 were male? What was the probibility that 6 or more were female? What

    asked on November 10, 2012
  29. physics

    Water is poured into a container that has a leak.The mass 'm' of the water is given as a function of time 't' by, m=5t^0.8 -3t + 20 , with t>=0, mass in grams and t in seconds A) at what time is the water mass greatest,and B) what is the greatest mass? In

    asked on October 19, 2014
  30. Economics/Finance

    How much Jim can accumulate in a private pension fund over 20 years if the fund offers 5% interest compounded annually, and he can afford to deposit $2,000 at the end of every 2nd year? My textbook says the correct answer

    asked on July 4, 2016
  31. Did you read The Pig Man And Me

    John Quinn does not explain the rule about the paddle to Paul, the narrator of “The Pigman & Me.” How does this one action affect the rest of the essay?

    asked on October 11, 2015
  32. Physics

    21) A 46 kg skater is standing still in front of a wall. By pushing against the wall she propels herself backward with a velocity of – 1.2 m /s. Her hands are in contact with the wall for 0.8 s. Ignore friction and wind resistance • Find the magnitude

    asked on December 4, 2012
  33. AP Chem

    At a certain temperature, 4.0 mol NH3 is introduced into a 2.0 L container, and the NH3 partially dissociates by the reaction. 2 NH3(g) N2(g) + 3 H2(g) At equilibrium, 2.0 mol NH3 remains. What is the value of K for this reaction?

    asked on January 8, 2012
  34. Statistics

    Recently, a case of food poisoning was traced to a particular restaurant chain. The source was identified and corrective actions were taken to make sure that the food poisoning would not reoccur. Despite the response from the restaurant chain, many

    asked on March 9, 2011
  35. World History

    (Need help with this prompt, just one paragraph will do) It is 1870, French forces leave Italy (to fight in the Franco-Prussian War) and Italians triumphantly declare Rome their united capital. You have been hired by Vittorio Emanuele II, the King of

    asked on March 4, 2017
  36. physics

    A block is pressed against a vertical wall by a force , as the drawing shows. This force can either push the block upward at a constant velocity or allow it to slide downward at a constant velocity. The magnitude of the force is different in the two cases,

    asked on June 30, 2013
  37. chemistry

    need formula to this. Carbon monoxide reacts with oxygen to produce carbon dioxide. If 3.0 Liters of carbon monoxide at STP, how many liters of oxygen are required to run the reaction

    asked on April 16, 2012
  38. Physics

    The space shuttle, with an initial mass M = 2.41×106 kg, is launched from the surface of the earth with an initial net acceleration a = 26.1 m/s^2. The rate of fuel consumption is R = 6.90×103 kg/s. The shuttle reaches outer space with a velocity of vo =

    asked on October 13, 2014
  39. Physics

    3 kg object is fastened to a light spring with the intervening cord passing over a pulley. The pulley is frictionless and it's inertia may been neglected. The object is released from rest when the spring is unstretched. If the object drops 10 cm before

    asked on February 5, 2015
  40. spelling paragraph

    I need to write a paragraph using the following words, acculturation,affable, aggrandize, approbation, callow, erudite, expedite, hackneyed, innuendo, inscrutable, intercede, peculate, querulous, remonstrate, repudiate, resilient, sedulous, tenuous Could

    asked on December 7, 2008
  41. physics

    You set your stationary bike on a high 80 N friction like resistive force and cycle for 30 min at speed of 8 m/s. Your body is 10% efficient at converting chemical energy in your body into mechanical work. What is your internal chemical energy change? How

    asked on January 20, 2015
  42. Statistics

    The weight of bags of pretzels are normally distributed with a mean of 150 grams and a standard deviation of 5 grams. Bags in the upper 4.5% are too heavy and must be repackaged. Also, the bags in the lower 5% do not meet the minimum weight requirement and

    asked on March 20, 2017
  43. Physics

    A quarter on a spinning vinyl record has a centripetal acceleration of 34.0 m/s2. What is the acceleration of the quarter if it is placed twice as far from the centre of the vinyl record?

    asked on September 27, 2017
  44. calculus

    A plane is flying west at 500 ft/sec at an altitude of 4000 ft. The plane is tracked by a searchlight on the ground. If the light is to be trained on the plane, find the change in the angle of elevation of the searchlight at horizontal distance of 2000 ft.

    asked on November 12, 2008
  45. Chemistry

    How many milliliters of 1.0 M NaOH must be added to 200. mL of 0.10 M NaH2PO4 to make a buffer solution with a pH of 7.50? (5 points)

    asked on April 4, 2013
  46. Calculus (Partial Derivatives)

    Using x hours of skilled labor and y hours of unskilled labor, a manufacturer can produce Q(x,y)=40xy1/5 units each week. Currently 20 hours of skilled labor and 243 hours of unskilled labor are being used. Suppose the manufacturer reduces the skilled

    asked on February 28, 2015
  47. physics

    A boy is pushing his sled up a snowy slope. The sled has a mass of 20.4 kg and weighs 200 N. The boy pushes with a constant force of 75 N. The sled travels a distance of 10 m and gains 3 m in height. When the sled reaches the top, it is traveling 2 m/s.

    asked on March 27, 2013
  48. Alegbra 1

    Mrs. Gifford's class consists of 15 girls and 25 boys. On the first test the mean of the girls’ scores was 80 and the mean of the boy’s scores was 70. What was the class mean? (Remember the class mean is not just averaging the two means)

    asked on December 15, 2017
  49. AP Chemistry

    The solubility of solid Ce(IO3)3 in a 0.20 M KIO3 solution is 4.4 10-8 mol/L. Calculate Ksp.

    asked on December 4, 2011
  50. Physics

    Need help ASAP for this one, really hard. to Assignment 11Problem 13.26 Tuning Forks in Neurology Tuning forks are used in the diagnosis of nervous afflictions known as large-fiber polyneuropathies, which are often manifested in the form of reduced

    asked on November 19, 2009
  51. Geometry- PLEASE HELP!!

    Point $G$ is the midpoint of median $\overline{XM}$ of $\triangle XYZ$. Point $H$ is the midpoint of $\overline{XY}$, and point $T$ is the intersection of $\overline{HM}$ and $\overline{YG}$. Find the area of $\triangle MTG$ if $[XYZ] =150$.

    asked on April 19, 2016
  52. maori english

    hey everybody. is there a difference between maori and maori english?i am totally confused now.I am supposed to write an important paper about maori english(phonology grammar etc.)and i am wondering if i have maybe mixed up those two and i am almoust

    asked on September 9, 2008
  53. Physics

    Because of the Earth's rotation, a plumb bob does not hang exactly along a line directed to the center of the Earth. How much does the plumb bob deviate from a radial line at 35.1° north latitude? Assume the Earth is spherical.

    asked on February 25, 2012
  54. spanish

    does anyone speak spanish please help. my friend has a question

    asked on July 31, 2019
  55. Accounting

    Which of the following is a reconciling item on the bank side of a bank reconciliation? a. both "outstanding checks" and "NSF checks" b. canceled checks c. outstanding checks d. NSF checks

    asked on March 31, 2019
  56. math

    Independent random samples, each containing 800 observations, were selected from two binomial populations. The samples from populations 1 and 2 produced 320 and 400 successes, respectively. Construct a 90% confidence interval for the true difference in

    asked on November 18, 2015
  57. chemessty

    What is the freezing point of an aqueous solution of 10.0 g of glucose (C6H12O6) in 50.0g H2O? (kf=-1.86 C/m)

    asked on March 16, 2011
  58. Physics

    A stone is dropped from a high altitude and 3 s later another stone is projected downward with a speed of 150 ft/s. When and where will the second stone overtake the first? Ans. (a) 5.70 s (b) 520 ft

    asked on September 24, 2011
  59. PreAlgebra

    If x=yz, which of the following must be equal to xy? a. yz b. yz^2 c. y^2z d. z^2\y

    asked on March 9, 2011
  60. Physics Concepts

    A father racing his son has one-third the kinetic energy of the son, who has two-fifths the mass of the father. The father speeds up by 1.5 m/s and then has the same kinetic energy as the son. What is the Father's initial speed? What is the Son's initial

    asked on March 5, 2011
  61. Please need help Asap

    Jenna invests in a savings account that has an annual interest rate of 12% compounded monthly. Jenna initially deposits $2673. How much money will Jenna have after 4 years?

    asked on March 12, 2018
  62. Math

    When calculating his income tax an accountant realized that his federal tax was 40% of his income after his provincial tax was paid, and that his provincial tax was 25% of his income after his federal tax was paid. If the accountant's income before taxes

    asked on October 12, 2019
  63. chemistry

    can O3, AsH3 and H2Se act as a lewis acid? please explain.

    asked on July 4, 2011
  64. math

    Sound travels at 343 meters per second. You measured 3 seconds for sound travel from place A to place B. What is the distance between and A and B?

    asked on November 27, 2018
  65. Algebra I

    It is the grand opening of a local supermarket. Every 5th customer will receive a coupon for a free turkey and every 7th customer will receive a coupon for a free half gallon of ice cream. If 400 customers come in on opening day, how many people will get

    asked on February 8, 2018
  66. Math/Economics

    Suppose that a firm has only one variable input, labor, and firm output is zero when labor is zero. When the firm hires 6 workers it produces 90 units of output. Fixed cost of production are $6 and the variable cost per unit of labor is $10. The marginal

    asked on October 18, 2011
  67. statistic

    Roll two 6-sided dice and examine their sum. a) How long will it take to roll "snake-eyes" (a pair of ones)? b) What is the probability of rolling a sum of 7 on the first roll? c) What is the probability of rolling a sum of 7 on the fourth roll? d) What is

    asked on April 1, 2014
  68. Chemistry

    A 0.528 gram sample of a metal, M, reacts completely with sulfuric acid according to: M+H2SO4 -> MSO4+H2 A volume of 205 mL of hydrogen is collected over water; the water level in the collecting vessel is the same as the outside level. Atmospheric pressure

    asked on October 16, 2012
  69. Math

    Allegiant Airlines charges a mean base fare of $89. In addition, the airline charges for making a reservation on its website, checking bags, and inflight beverages. These additional charges average $35 per passenger. Suppose a random sample of 60

    asked on June 28, 2019
  70. Chemistry

    What element forms an ion with an electronic configuration of [Xe] and a –2 charge?

    asked on October 28, 2012
  71. AP Chem

    The Ksp for silver sulfate (Ag2SO4) is 1.2 10-5. Calculate the solubility of silver sulfate in each of the following. 0.30 M K2SO4

    asked on December 4, 2011
  72. Chemistry

    State the relationship between normality and molality

    asked on May 15, 2018
  73. Chemistry

    Calculate the pH of a 1.19M sodium formate, HCOONa, solution.

    asked on November 23, 2014
  74. calculus related rates

    Boyle’s law for the expansion of a gas is PV = k, where P is the pressure (in pounds per unit of area), V is the volume of the gas, and k is a constant. Find the expression that shows the rate of change of the pressure as related to the rate of change of

    asked on November 11, 2014
  75. physics

    Sphere 1 has surface area A1 and volume V1 and sphere 2 has surface area A2 and volume V2. If the radius of sphere 2 is 3.53 times the radius of sphere 1, what is the ratio of the areas A2/A1 ? 1.25×101 & 4.40×101 are correct answers but i dont remember

    asked on December 5, 2017
  76. Social Studies

    What examples are given of a limited government and an unlimited government in the section? How did each type of government affect its citizens? Japans government

    asked on October 5, 2015
  77. physics - college

    An unmarked police car traveling a constant 95km/h is passed by a speeder traveling 14km/h .Precisely 2.50s after the speeder passes, the police officer steps on the accelerator; if the police car's acceleration is 2.30m/s^2 , how much time passes before

    asked on April 15, 2012
  78. Chemistry

    Consider the following reaction. CH4(g) + 2 O2(g) CO2(g) + 2 H2O(l) ÄH = -891 kJ Calculate the enthalpy change for each of the following cases. 1.00 103 L methane gas at 719 torr and 26°C is burned in excess oxygen.

    asked on November 13, 2011
  79. Physics

    A small ball of mass m is placed on top of a large ball of mass 3m. Both balls are dropped simultaneously from a height h = 5.50 m as shown in the figure. Assuming the radius of the large ball and small are small and thus negligible in comparison to the

    asked on July 11, 2018
  80. math

    Eight people rob a bank: What percent of the loot belongs to three people if they decide to share it evenly

    asked on July 29, 2016
  81. Physics

    A 1000-kg aircraft going 25 m/s collides with a 1500-kg aircraft that is parked. They stick together after the collision and are moving at 10 m/s. If they skid for 30 seconds before stopping, how far (in meters) did they skid? Hint: Are the aircraft moving

    asked on January 30, 2016
  82. AP Chem

    The following reaction has Kp = 109 at 25°C. 2 NO(g) + Br2(g) 2 NOBr(g) If the equilibrium partial pressure of Br2 is 0.0159 atm and the equilibrium partial pressure of NOBr is 0.0768 atm, calculate the partial pressure of NO at equilibrium.

    asked on January 8, 2012
  83. Chemistry

    How many grams of HCl are produced according to the following equation, H2 + Cl2 = 2 HCl, when 4.0 g of hydrogen reacts completely?

    asked on October 25, 2010
  84. physics

    A bee flies to a flower 583 m due south of its hive. The bee’s speed in still air is 0.68 m/s, and there is a wind blowing toward the south at 0.16 m/s. How long will it take the bee to travel to the flower and back to the hive? Answer in units of s

    asked on November 18, 2014
  85. Statistics

    In order to compare two kinds of feed, thirteen pigs are split into two groups, and each group received one feed. The following are the gains in weight (kilograms) after a fixed period of time: Feed A: 8.0 7.4 5.8 6.2 8.8 9.5 Feed B: 12.0 18.2 8.0 9.6 8.2

    asked on February 18, 2013
  86. physics

    What is the average useful power output of a person who does 5.50×106 J of useful work in 6.50 h? Working at this rate, how long will it take this person to lift 1850 kg of bricks 1.20 m to a platform? (Work done to lift his body can be omitted because it

    asked on November 17, 2017
  87. science

    How do scientists explain the fact that some landforms that are far apart and separated by oceans appear to be related?

    asked on December 14, 2016
  88. Physics

    Carl hits a 0.05 kg golf ball giving it a speed of 65 m/s. What impulse does he impact to the ball?

    asked on March 6, 2015
  89. physics

    A plane cruising at 247 m/s accelerates at 28 m/s 2 for 8.7 s.How far will it have traveled in that time?

    asked on October 22, 2014
  90. physics - college

    An unmarked police car traveling a constant 95km/h is passed by a speeder traveling 14km/h .Precisely 2.50s after the speeder passes, the police officer steps on the accelerator; if the police car's acceleration is 2.30m/s^2 , how much time passes before

    asked on April 15, 2012
  91. Chemistry

    55g of CF2Cl2, how many grams of Cl do I have? How do I solve this kind of problem?

    asked on March 12, 2011
  92. Chemistry

    A 3.50L balloon contains 0.178 mol of gas. If 0.094 mol of gas is added to the balloon, what will be the new volume?

    asked on March 2, 2016

    How are fish, amphibians, reptiles, and birds alike? How are they different? Include at least two similarities and two differences.

    asked on October 7, 2015
  94. Calculus (Partial Derivatives)

    A car dealer determines that if gasoline-electric hybrid automobiles are sold for x dollars apiece and the price of gasoline is y cents per gallon, then approximately H hybrid cars will be sold each year, where H(x,y)=6000−13x^(1/2)+2(0.1y+20)^(3/2). She

    asked on March 4, 2015
  95. math

    farmer fred had chickens and cows on his farm. he knows that together there are 108 legs and 30 heads. how many of each type of animal does he have?

    asked on October 12, 2011
  96. physics

    A certain car is capable of accelerating at a rate of +0.60 m/s2. How long does it take for this car to go from a speed of 20 mi/h to a speed of 65 mi/h?

    asked on September 21, 2010
  97. Physics

    A stone, initially at rest, is dropped from the top of a building. On its way down, it passes a window that is 2.52m tall. It takes 0.134 seconds to pass the window. From how far above the top of the window was the stone dropped?

    asked on October 12, 2009
  98. Maths

    Which equation has (2, -1) as a solution? a. y = 2x - 1 b. y = x + 3* c. y = x - 3 d. y = -2x +1 check my answer plz

    asked on February 24, 2019
  99. chemistry

    The enthalpy of neutralization for the reaction of a strong acid with a strong base is -56 kJ/mol of water produced. How much energy will be released when 185.0 mL of 0.400 M HCl is mixed with 152.5 mL of 0.500 M NaOH?

    asked on November 13, 2011
  100. Math

    jose invests 3,250 at a 6% interest compounded anually. What will be the balance in the account after 3.5 years. a. 3,032.50 b. 3,985.23 c. 4,752.00* d. 5,200.00 check plz

    asked on February 21, 2019


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