Questions Asked on
March 6, 2009

  1. Calculus-Modeling Equations

    An unknown radioactive element decays into non-radioactive substances. In 420 days the radioactivity of a sample decreases by 39 percent. 1.What is the half-life of the element? 2.How long will it take for a sample of 100 mg to decay to 46 mg?

    asked by Kim
  2. Chemistry

    If 2.50 g of CuSO4 are dissolved in 9.4 102 mL of 0.34 M NH3, what are the concentrations of Cu(NH3)42+, NH3 and Cu2+ at equilibrium? i tried doing Cu2+ first and i did Kf=5e13= salt/cu2+ nh3+^4 and i did molesCuSO4/.94 L = .01666 M salt so then i did

    asked by Justin
  3. Organic Chesmitry

    The purpose of a gas trap in the Diels-Alder reaction set up is to A. Trap oxygen gas B. Trap the diels alder product C. Trap sulfur dioxide gas D. Trap carbon dioxide gas E. Trap nitrogen gas

    asked by nilee
  4. writting

    unless you are luckier than most,hundreds of other people will also have discovered your natural paradise. a)replace you with one b)change than to then c)change discovered to been discovered d)no correction neccesary

    asked by jessica
  5. Organic Chemistry

    The purpose of adding concentrated H2SO4 to the Diels-Alder adduct was to: A. hydrolyze the product to make the product precipitate more easily B. catalyze the diels alder reaction C. use Le Chatelier’s principle to drive the reaction to completion D. to

    asked by nilee
  6. writting

    what correction should be made? some just look forward to the perspect of watching birds and animals,such as rabbits or deer,in thier natural habitats. a)change look forward to looks forward b)change the spelling of perspect to prospect c)insert a comma

    asked by jessica
  7. writting skills

    what correction should be made to this sentence? one of the lifelong memories many of us share are the moment we obtained a driver's license? a)change the spelling of memoreis to memorys b)inset a comma after memories c)change are to is d)change driver's

    asked by jessica
  8. Chemistry

    I need predict the bond type for NaCN. Also, for covalent molecules, specify also whether the molecule as a whole is polar?

    asked by Aileen
  9. Organic Chemistry

    Why is 4-chlorophenol soluble in 2.5M NaOH solution, but not in water? A. Phenol is a weak acid so it can be deprotonated under basic conditions. B. Aqueous acid destroys 4-chlorophenol. C. 4-chlorophenol is only soluble in water at low temperature. D. A

    asked by nilee
  10. Algebra

    How do I solve for the elimination method: 5x + 3y= -7 and 7x - 2y =13 (step 1); 10x + 6y =-14 and 21x -6y = 39 ( step 2), 31x/31= 25/31, x= 25/31 (step 4). But after that I get lost. Can somebody help me out please.

    asked by A.W.
  11. math

    how can i find the perimeter of a semi circular flower bed of diameter 20m?

    asked by help
  12. English

    1. What do the pictures remind you of? They remind me of my childhood. They remind me of love. They remind me of life. They remind me of babies. They remind me of the importance of life. They remind me of the word cute. 2. What do the pictures make you

    asked by John
  13. English

    What do you have to do if you want make the bee land on the flower? (situation: On a page, there is a flower on the left side. Thereis a bee on the right side. There is a thick verticle line between them.) I will try to cut the line. I will fold the page.

    asked by John
  14. Physics

    The average emf induced in the secondary coil is 0.12 V when the current in the primary coil changes from 3.8 to 1.1 A in 0.14 s. What is the mutual inductance of the coils?

    asked by nj
  15. Organic Chemistry

    You perform a Diels-Alder reaction using 2.0 g butadiene sulfone (MW=118.15 g/mol), 1.2 g maleic anhydride (MW=98.06 g/mol) and 0.8 mL xylenes (MW=318.5 g/mol, density=0.862 g/mL). What is the theoretical yield of the reaction? A. 0.017 mols B. 0.052 mols

    asked by nilee
  16. 2nd grade fraction question

    Only using the numbers 0-9 once each is it possible to make 5 fractions that are less than 1/2?

    asked by Arianna
  17. Jiskha

    Good evening everyone, I just wanted to know why people on this computer keep getting blocked from this site...I tried to ask and answer questions a couple of days ago and was unable to because I was obviously blocked. Whenever i pressed 'Submit Question'

    asked by mysterychicken
  18. chemistry

    1.)What is the boiling point of the water in your radiator if 2.00kg of antifreeze is added to 9.00 * 10^3 grams of water? 2.)Assuming that each system behaves ideally, which solution (0.25 m KCl or 0.25 m C3H8O3)would have the lower freezing point?

    asked by blah..unsure..plz help!!
  19. Organic Chemistry

    Which of the following products of the acid-catalyzed elimination of 2-pentanol is the Hoffmann elimination product? A. trans-2-butene B. cis-2-butene C. 1-butene

    asked by nilee
  20. English

    Your are future seeds. What is your future hope? Jihyeon's future hope is to become an announcer. Write down what she had to do the achieve her dream. 1. I will try to read a book every day. 2. I will try to drink orange juice from time to time. 3. I will

    asked by John
  21. biology

    Predict what would happen to a red blood cell placed in each of the following external solutions. Would it shrink, swell, or not change its volume? Explain each answer in ONE sentence. a. 150 mM NaCl b. 100 mM NaCl plus 50 mM albumin

    asked by erin
  22. Math

    On Tuesday Grac4e's flower shop sold 124 flowers. At the end of the day, there were 237 flowers left in the shop. Grace use the equation below to find the total number of flowers, f, that were in the shop at the beginning of the day. f-124=237

    asked by Carol
  23. Organic Chemistry

    The Diels-Alder reaction is classified as a: A. polar reaction B. radical reaction C. substitution reaction D. pericyclic reaction E. rearrangement reaction

    asked by nilee
  24. 7th grade science

    problem:suppose a bacterium reproduces by binary fission every 20 minutes.the new cells survive and reproduce at the same rate. this graph shows how the bacterial population would grow from a single bacterium. use the graph below to show your results up to

    asked by christopher crawford
  25. Organic Chem

    Potassium tert-butoxide is a common base for E2 reactions because it is _______. A. weak base B. an organic base C. a strong base D. a bulky base

    asked by nilee
  26. algebra

    (5a³b)²/10a²b How would I begin solving this? Thank you!

    asked by Cassie
  27. English

    Look at the picture on the left. This is a plant. there are two leaves on the plant. They are new buds. The buds seemed to have been opened just now. Look at the picture on the top right. There are many beautiful flowers in the picture. Spring is the

    asked by John
  28. Organic Chemistry

    Order the following in order of increasing bond vibration frequency: O-H, sp3 C-H, sp C-H, sp2 C-H A. O-H < sp3 C-H < sp C-H < sp2 C-H B. sp3 C-H < O-H < sp2 C-H < sp C-H C. sp2 C-H < sp3 C-H < sp C-H < O-H D. sp3 C-H < sp2 C-H < sp C-H < O-H E. O-H < sp

    asked by nilee
  29. Algebra

    How do I solve for elimination method on this problem: 0.3x - 0.2y=4 and 0.3x + 0.3y= 5/19. I know that multiply by 10 on both equations and get 3x-2y=40 and 3x+3y=50/19. and then I have to multiply 3x-3y=40 by 3 and 3x+3y= 50/19 by -3 to get 9x-9y=120 and

    asked by A.W.
  30. Organic Chemistry

    How many peaks would be expected in the 1H NMR spectrum for mesitylene? A. 2 B. 6 C. 3 D. 12 E. 9

    asked by nilee
  31. English

    1. After you take a look at the pictures below, say what reminds you of. 2. Say your new hopes about the new year. 3. About What the story about courage and curiosity What will you learn? Saying the degree is the same Saying sensible feeling Answering the

    asked by John
  32. biology repost

    Predict what would happen to a red blood cell placed in each of the following external solutions. Would it shrink, swell, or not change its volume? Explain each answer in ONE sentence. a. 150 mM NaCl b. 100 mM NaCl plus 50 mM albumin

    asked by erin
  33. math

    an 80 foot flag pole casts a 30 foot shadow . find the height of the tree if its shadow is 9 feet

    asked by erika
  34. Algebra

    Find x if 2^16^x = 16^2^x Just to make this clear, if you were reading this aloud, it would sound like this: if 2 to the power of 16 to the power of x equals 16 to the power of 2 to the power of x. So basically, the x would not be the same size as the 2 or

    asked by Cassie
  35. 6th grade

    what are trannosaurus rex famous for

    asked by annomys
  36. Chemistry help please!

    For each product of the following unbalanced equations which reactant is limiting, and calculate the mass of each product that is expected. 1) 2Al + 6HCL --> 2AlCl2 + 3H2 15.0gAl * 1moleAl/26.981gAl * 2moleAlCl3/2moleAl * 133.34gAlCl3/1moleAlCl3=

    asked by Chopsticks
  37. biology

    Predict what would happen to a red blood cell placed in each of the following external solutions. Would it shrink, swell, or not change its volume? Explain each answer in ONE sentence. a. 150 mM NaCl b. 100 mM NaCl plus 50 mM albumin

    asked by erin
  38. Organic Chemistry

    When performing a dehydration reaction, what may be done to drive the equilibrium to the right: A. removal of the product as it is formed B. increasing the concentration of the solvent C. doubling the concentration of the acid catalyst D. lowering the

    asked by nilee
  39. Organic Chemistry

    In order to obtain pure synthetic plant hormone, a 2:1 mixture of water and ethanol is used as the crystallizing solvent. Why is a solvent mixture used? A. Organic compounds are not soluble in pure ethanol. B. Ethanol and water have similar boiling points,

    asked by nilee
  40. english

    Please any one help me which one of the following is correct? When winter comes, the days get colder. When winter comes, the days get coldest. please explain

    asked by ramesh reddy
  41. french mme sra

    I think I have done all the corrections. Please could you tell me if there's anything else wrong. Thankyou Pour le petit déjeuner ce matin j’ai mangé une banane et des raisins et j’ai bu de l’eau mais d’habitude je mange un bol de céréales et

    asked by valerie
  42. Essay

    Does an interview that I conducted for a research paper need to be sited on a reference page if the paper is written in APA format?

    asked by JaneDawn
  43. Organic Chemistry

    What is the theoretical volume (at STP) of butene product that can be obtained from the dehydration of 0.412 g of 2-butanol? (MW = 74 g/mol; 22.414 L/mol) A. 125 L B. 1.36 L C. 125 mL D. 0.000248 L Can you please show calculations

    asked by nilee
  44. Organic Chemistry

    In order for the E2 elimination of an alkyl bromide to occur, the β-hydrogen and the bromide leaving group must have ____________ arrangement. A. an orthoganol B. a syn C. an anti-periplanar D. an eclipsed

    asked by nilee
  45. Math/Algebra

    Find the x-intercepts of f(x)=4x^2-20. Give an exact answer using radicals as needed. Rationalize all denominators. Express complex numbers in terms of i.

    asked by Kelly
  46. Organic Chemistry

    In order for a Diels-Alder reaction to take place the diene must be in what conformation? A. cis B. trans C. s-trans D. anti E. s-cis

    asked by nilee
  47. Organic Chemistry

    Which of the following would have the lowest stretching frequency A. C=C B. C-O C. C=O D. N=O E. C-H

    asked by nilee
  48. physics

    if acceleration is -9.8, initial velocity is 10, initial position of a point is +0.5m. then when does it pass y=0 and what is the velocity at that time

    asked by sweety
  49. math

    x-8y=18 -16x+16y=-8

    asked by sierra
  50. French

    If I want to say, "Anne likes when school closes and vacation begins," would the following be correct: "Anne aime quand l'ecole fermer et les vacances commencer"?

    asked by Anonymous
  51. French

    What does the following sentence mean?: "Huit hommes habitent en bas." Does it mean, "Eight men live... low?.."? I'm not sure about the "en bas" part. It doesn't really make sense with the rest of the sentence.

    asked by Anonymous
  52. Math

    Have to do an enlargement project and enlarge an everyday item by 10 times it original size. Part of grade is level of difficulty so do not want to do something simple. Older sister did a lego piece. Need some good ideas on a item and am stumped!

    asked by Marissa
  53. Financial Management

    Does anyone know how to do Time Series Regression. I need to learn to do this for my HHS 265 class. Please share with me the steps to this process.

    asked by Patricia
  54. algebra

    Find the slope, it it exists x+7y=14 x=7y/14=2 check this problem for me please

    asked by jj
  55. stats

    chi square for independence 1) my obtained value does not exceed the critical value, I will reject the alternate and accept the null. Do I state that the results is due to chance and there is no relationship between the variables.

    asked by Anne
  56. Organic Chemistry

    The E1 elimination reaction proceeds through a _________ . A. concerted process B. carbocation intermediate C. polarized transition state

    asked by nilee
  57. NUL University

    predict the bromination rates of the following aromatic compounds: Chlorobenzene, methoxybenzene, Nitrobenzene, Benzene and Toluene

    asked by Poloko
  58. French

    Also, how would I say, "The classes are over for the weekend"? Les classes ont fini pour le week-end. ?

    asked by Anonymous
  59. English

    What is your hope for the new year? What is your hope about the new year? What is your hope for a new year? What is your hope about a new year? (Which one is correct?)

    asked by John
  60. AE is this correct?

    determine the teachercertification/licensure requirements for the state you would like to teach in. I picked wisconsin and i put this...... Initial In-State Teaching or Pupil Services - PI-1602-IS Graduates of Wisconsin educator preparation programs only.

    asked by scooby91320002
  61. Human Resources

    What are the four steps an organization should change its personality profile. What should the organization consider before developing a plan.

    asked by Lisa
  62. Romeo and Juliet Help

    I'm still confused about this question could someone please assist me thanks. When Lady Capulet asks Juliet how she feels about her being married. What is Juliet's answer (line 72 in act 1 scene 3) and what does this reveal about her character. I know the

    asked by Anonymous
  63. chem

    a solution that is 0.51 M CH3COOH and 0.28 M CH3COONa is that a buffer? when can u tell when to us the henderson hasslebach

    asked by Rick
  64. Algebra

    Find the y-intercept and the x-intercept for the equation. -6x+y=22 What is the y-intercept. Type an ordered pair. y is (0,3) What is the x-intercept, Type an ordered pair. x is (0,0) Could check this problem to see if right.

    asked by Elaine
  65. Organic Chemistry

    Bond vibration frequencies are directly related to: A. The amount of atoms in a compound B. The electronegativity of the atoms C. The amount of sample on the IR plate D. Mass of the atoms E. All of the Above

    asked by nilee
  66. Literacy

    How do you use quotation marks when you're quoting a quote?

    asked by Angie
  67. grammar

    what is a vague pronoun?

    asked by jewels
  68. Wilders Preparatory

    What are the modifiers for the word flexible?

    asked by Erin
  69. French Revolution

    5 song names from before French Revolution (3 can be made up, but MUST reflect the ideas of the time) 5 song names from after French Revolution (3 can be made up, but MUST reflect the ideas of the time) 1 or the songs from each (2 total) must include

    asked by Larry
  70. math

    this is an easy question, but i kept doing this in my calculator but my answer always showed up wrong. a = (0-(20.5 m/s))^2)/(2(1.18 (x ) 10^2 ( m) =

    asked by cb
  71. math

    this is an easy question, but i kept doing this in my calculator but my answer always showed up wrong. a = (0-(20.5 m/s))^2)/(2(1.18 (x ) 10^2 ( m) =

    asked by cb
  72. business law

    can a shareholder get his dividends after being dismissed by the others? Thnx!

    asked by Sabi
  73. Organic Chemistry

    Where would one expect to see a peak corresponding to a carbonyl group A. 1350-1500 B. 1625-1800 C. 1700-1825 D. 1775-1900 E. 1625-1850

    asked by nilee
  74. English

    1. Find what the two seeds said and match them. 2. Choose the things (sentences) which are not suitable for the reading text. 3. Write down the lesson of this story and compare it with your classmate's. 4. Your futures and dreams are like beautiful flowers

    asked by John
  75. English

    1. Jane has got 90 points. Mike has got 90 points as well. So Jane is as smart as Mike. They have the same degree of score. 2. Jane has lifted 20 kg weights. Mike has lifted 20 kg weights. Jane is as strong as Mike. So they hav e the same degree of

    asked by John
  76. Science

    I am doing a power point on hydraulic brakes but I can't find any diagrams of a simple hydraulic brake that points out all the parts but isn't to hard to understand like th ones in the textbook. Does anyone know of any good pictures on the web? thanks:)

    asked by Nick
  77. French

    How would you say, "Roger likes not having classes"? Roger aime.... pas avoir?.... les classes. ?

    asked by Anonymous
  78. Religion

    What is the baptist view on Abortion?

    asked by Connor
  79. Romeo and Juliet HELP

    Could you please, please help me with this quick question thanks and god bless. IN line 72 what does Juliet's answer reveal about her character? I'm not sure could you please help me thanks.

    asked by Anonymous
  80. Human Resources

    What are the three ways humans help support the strategic goals of service organization.Provide examples to support your answers.

    asked by Lisa
  81. Organic Chemistry

    Rearrangement In Sn2 reactions do not occur because A. they are especially fast and hence do not have time to rearrange. B. it goes through a concerted transition state with no carbocation intermediate. C. you do get rearrangements in Sn2 reaction D. None

    asked by killie
  82. ALgebra

    what would the x intercepts be for this equation? y=x^2-3x-4 thanks.

    asked by Sammy
  83. Organic chemistry

    what is the relative bromination rates of the following aromatic compounds; clorobenzene, methoxybenzene, nitrobnzene, toluene, benzene

    asked by Alinah
  84. eng

    Can someone please explane Dr. Wade's airplane analogy?

    asked by sue
  85. Romeo and Juliet HELP

    Could you please, please help me with this quick question thanks and god bless. IN line 72 what does Juliet's answer reveal about her character? I'm not sure could you please help me thanks.

    asked by Anonymous
  86. Math

    find the rate. 260 lbs of fertilizer divided by 5 lawns

    asked by Jay
  87. World Cultures

    In my Italy report, I'd like to explain about a form of Italian folk dancing that I have heard about. However, I do not know how to spell it. It is pronounced vi-vach-ee, and I tried googling vivace and vivacci, as well as vivaci, and I found no related

    asked by Kyla
  88. english

    how should i write an essay with this q.? " How has ur studying of ur prescribed text (Othello) and 2 related pieces of material (A Drive in the country by Peter Skryneski and Riots and revenge) broaden ur understanding of change?"

    asked by Craddi
  89. AE....

    How can diversity be an asset to the classroom?

    asked by scooby91320002
  90. anthropology

    what are the two leading countries today

    asked by cynthia
  91. Organic chemistry

    what is the relative bromination rates of the following aromatic compounds; clorobenzene, methoxybenzene, nitrobnzene, toluene, benzene

    asked by Alinah
  92. maths

    how do i find the area of a semi circle with a radius of 6 cm rounded to 2dp?

    asked by hello
  93. Math

    How do you do this: 1/2(3ã3)(18)

    asked by Christopher
  94. Alegebra

    Use the intercepts to graph the equation. 4x-12=3y It should be pair. is the answer (4,3)

    asked by Elaine
  95. Math

    Is it possible using the numbers 0-9 to make 5 fractions that are less than 1/2?

    asked by Arianna
  96. MATHS

    60* 7/3

    asked by Muslimah