# Questions Asked onMarch 6, 2007

1. ## math, algebra

what are some challenges about working with rational expressions? Math is a language. Getting it precisely right is a lot easier than describing it in a vague statement in English such as you ask. Is there a chance you can change teachers? If so, I

2. ## psychology

In a study, a few students did the number Stroop and color Stroop. They showed much less interference on the numbers than they did on the color task. Why does this make sense? Please check these sites. If you post your answer, we'll be glad to comment on

3. ## chemistry

help required in calculating the pH value of a .84 mols per litre solution of sulfuric acid. I understand that pH = -log 10 (2x 0.84), I am not very experienced with logs and need assistance as to which keys to press on the scientific calculator in

4. ## science

A 0.21 g of Sulfuris acid is dissolved completely in sufficient water to make 0.25 litre of final solution. Calculate the hydrogen ion concentration (in mol 1 -1) in this solution. Give your answer in scientific notation to an appropriate number of

5. ## Chem

using the properties of sodium cyanide , deduce the type of bonding that holds this compound together, explaining how you arrived at your conclusions. write a balances equation for the reaction that occurs when sodium cyanide dissolves in water. Any help

6. ## science

In the process called fluorescence, some substances absorb photons of one kind of radiation (e.g) ultraviolet radiation), and give out photons of a different kind (e.g visible light). When infrared radiation falls on these materials, visible light is not

7. ## chemistry

The isotype caesium -137, which has a half life of 30 years, is a product of nuclear power plants. How long will it take for the amount of this isotype in a sample of caesium to decay to one-sixteenth of its original amount? first half life 1/2 second 1/4

8. ## Math, Calculus

Find the derivative of the function. y= xcosx - sinx What's the derivative? I get only one trig function. I will be happy to critique your work or thinking. Use the chain rule on the first term. Our class hasn't covered Chain Rule. Only product and

9. ## Chem

I have a problem in which I'm solving for -w. My equation is this: -w= nRT ln V2/V1 However, I don't know the value of n, but I do know the values of P, V, and T. If I fill in (PV/RT) for n in the above equation, would I be using the energy R or the gas R?

10. ## chemistry

please can u help i need to a structure of a polymer and i dentify the monomer unit and include three monomer units,from the compound CH2=CH-CH-OH CH3 AND STATE THE POLYMERIZATION INVOLVED IN FORMING THE POLYMER,please help i have tried ,but i cant make

11. ## World war one! thanks!

Right before the war Imperialistic, territorial, Nationalism and economic rivalries had been intensifying among Germany, France, Great Britain, Russia, and Austria-Hungary. The Balkan war was from 1912 to 1913; all the major powers increased in size as

asked by essay+ can some edit my paragraph?Thanks!
12. ## geometric sequence

how whould u find the next 3 terms of sequence 18,9,9/2,9/4 Each term is the last multiplied by 1/2. dont got one i think that is right

13. ## Science

A drop of oil (volume 0.05cm3) is released from a medicine dropper on to the calm surface of a pond where it spreads out to cover an area of "40cm2". Assume that the oil film has a uniform thickness equal to the diameter of a oil molecule. Calculate the

14. ## math help major test

which numbers are four units from -1? It may help to look at a number line like the following (as an example): Can you determine which numbers (both negative and positive) could be 4 units from -1 ? I'm not sure if this is what you were asking, but I hope

15. ## Quantum Physics

Each element has a different set of energy levels. Use this fact to "explain" whay the colour of the light emitted by an element in the gaseous state is characteristic of the element. When an electron falls from one of the higher energy levels to a lower

16. ## Science

Explain, with the help of an appropriate labelled sketch diagram, how a hydrogen atom, which has only one electron, has so many spectral lines. The diagram of the energy levels follows: --------------- --------------- --------------- -----------------

17. ## help me math

if the percent was 56 what would the fraction value be and the decimal value Please read my previous answer to "kate" http://www.jiskha.com/display.cgi?id=1173141658

18. ## SCIENCE

Which action would result in more (financially) valuable product: taking one proton from each nucleus in a sample of gold or adding one proton to each gold necleus? Explain (ignore the role of elections on the atom) Make the protons add up. 79Au ==> 1p +

19. ## Chemistry

The isotope caesium-137, which has a half life of 30 years, is a product of neuclear power plants. How long will it take for the amount of this isotope in a sample of caesium to decay to one sixteenth of its original amount. Explain answer 30 years 1/2 60

20. ## major math

which numbers are four units from -1? 3, -5 are both four units away on the real number line.Donna E. Shalala

21. ## math

if the percent was 56 what would the fraction value be I will be happy to check your work on this. Percent means per 100, or /100

22. ## math

if you simplify 15/72 would it be 5/24 yes or no? Yes

23. ## Written Communication

How would you approach creating a negative message for a superior (such as a menager at work or an instructor) versus creating a message for a colleague, subordinate, or fellow student. The basic difference to me is that you cant afford to tell a manager

24. ## frankenstein

for this question is the answer true One sign that Frankenstein is declining during his study is that he becomes unresponsive to the beauty of nature

25. ## frankenstein

for this question is the answer true Frankenstein says, "Like Adam, I was apparently united by no link to any other being in existence http://www.kimwoodbridge.com/maryshel/knowledge.shtml read the last 4 paragraphs. Then also

26. ## Chem

Concerning compounds cyanogen, Hydrogen cyanide and sodium cyanide. Cyanogen = C2N2 (CN)2 Hydrogen Cyanide = HCN boils at 26C and yeilds an acid solution when added with water. Sodium Cyanide = empirical formula NaCN is a solid melts at 564C a) Assuming

27. ## Chem

Concerning compounds cyanogen, Hydrogen cyanide and sodium cyanide. Cyanogen = C2N2 (CN)2 Hydrogen Cyanide = HCN boils at 26C and yeilds an acid solution when added with water. Sodium Cyanide = empirical formula NaCN is a solid melts at 564C a) Assuming

28. ## English

We are putting together a scrapbook for my older sister, and we came up with some dictionary definitions for parts of her name, but does anyone know of a meaning for "Valaitis"? Thanks for any help. Thank you for using the Jiskha Homework Help Forum. What

29. ## U.S History

Hey, I have a research paper for my college U.S History class and I'm having the hardest time thinking of a topic! It can be about absolutely anything that is correlated with U.S history. I'm sort of interested in World War II, and the Andrew Jackson era.

30. ## Math

Round 427,685 to the nearest thousand. 428,000

31. ## physiology (nernst equation)

If cell depolarises at +50mV, what are the concentrations of K+? I am really confused how to use the nernst equation to get the concentrations. If I set up 58 [Kout]/[Kin] = 50, will that be right? I am not sure how to start this problem.

32. ## variables

what makes variables difficult to understand?

33. ## Complex Analysis

Use the Cauchy Integral formula to evaluate foC (closed curve) f(z) dz, where C is oriented anticlockwise, for f(z) = (z + i)^2 / (z + 3 - 2i)^3 and C is the circle |z + 2| = 5. Thanks.

34. ## general science

What are the four main directions? Check this site for the four cardinal (main) directions. http://worldatlas.com/aatlas/infopage/comprose.htm

35. ## Math Probabilities

A bag contains 9 red chips and 12 blue chips. Two chips are selected randomly without replacement from the bag. What is the probability that the two chips are the same color? That would be the probability of two reds PLUS the probability of two blues. The

36. ## Raj....English Thesis

My teacher said that I only put that he "appears" to be a hypocrite, and that I need to clearly state if he is a hypocrite or not. Also, by putting "and three examples can be cited to demonstrate this trait of his", is a pretty weak thesis, she says. I

37. ## Science

Should there be more or less exploration and mining on public lands in the United States? Explain your answer. What is your answer? Please post it, and we'll be glad to comment on it.

38. ## information literacy

what year was the oldest copy of Ralph Ellison's Going to the Territory published? That book was published in l986

39. ## Info. literacy

what is the call number of the oldest copy of Ellison's Shadow and Act? Ask your librarian for the call number for her library on that book what is the call number of the oldest copy of Ellisons shadow and act

40. ## Physics

In a game of pool the cue ball strikes another ball of the same mass and initially at rest. After the collision the cue ball moves at 3.50 m/s along a line making an angle of 22 degrees with its original direction of motion. and the second ball had a speed

41. ## english

I am creating a resource page for an essay. Problem is a lot of my citations came from the same online encyclopedia which list its author as "Wikipedia contributors" So all the pages reference the same except the article title and url. The in text citation

42. ## Science

which would be the most likely forms that you would consider using within the next year? What personal advantages or disadvantages would prompt your decision? Thank you for using the Jiskha Homework Help Forum BUT your question is unclear. When you refer

43. ## Spanish

How would you conjugate the verb "decir" which means to say, to the "yo" form? Would it be digo? Or dico? Please help! Thank you for using the Jiskha Homework Help Forum. The verb "decir" is irregular in the "yo" form of the Present Indicative Tense: digo,

44. ## math

how do you8 find unit rate divide quantity by time. For instance, one travels 45 miles in 1/2 hour. Unit rate= 45/.5=90miles/hr the answer to your problem is x=18 the answer to your problum is x=18

45. ## Chem

I don't believe I'm getting the correct answers for this problem. Could someone look over my work and verify whether it is correct or not? One mole of an ideal gas (Cv = 3/2R) at 300. K expands adiabatically against a constant external pressure of 2.00 atm

46. ## Language Arts

Could someone read the passage and please tell me which answer is correct? Some kids collect coins. I can't keep a quarter without spending it. Some kids collect stuffed animals. Cute, but my room is the size of a closet. Where am I going to put alot of

47. ## Math- fraction equations

How would I solve this equation? d-1 = -1 1 ____ ___ 4 2 (d-1) divided by 4 = -1 and 1/2 Thanks, Ok, I'll set up your problem this way: (d-1)/4 = -1 1/2 -1 1/2 is the same as -3/2. Therefore: (d-1)/4 = -3/2 Multiply each fraction by a common denominator,

48. ## English

If someone made the statements to you, Asian Americans and Pacific Islanders are a model minority, and Asian Americans and Pacific Ishanders belong to a single "Asian American" culture. How would you explain that the statements are misconceptions? Include

asked by jenna williams
49. ## Math

My question is to get a better understanding of this. Basically, these two problems, I did it WITHOUT replacement. So I would multiply each defects and so forth. My question is, would I have to subtract the total from 1 in the second question? I am not

50. ## humanities

I am writing a short monologue on a person who chooses not to believe in any religion, but its back in when religion was not an option, in greece in like 300 BCE How can it improve, what can I add? Why do we act this way? Us humans, worshiping immortals

51. ## social studies

what do people who live in mozambique wear on their day to day activities http://www.google.com/search?source=ig&hl=en&q=mozambique There are all kinds of sites to sift through here. If you find nothing, you might try refining the search to mozambique

52. ## chemistry

Can someone please check my work on this problem? That'd be great!: What is the balanced equation for the chemical change of adding Na2CO3 to CuCl2, therefore making CuCO3 form? CuCl2+Na2CO3-->CuCO3+2NaCl right thank you fill in the blanks! Nuclear

53. ## Calculus

I know how to find the interval of convergence, but I don't understand when to check for convergence at the endpoints (to see if I should include it or not) Could someone help me understand this? Thanks!

54. ## algebra

How do you simplify this expression, assuming all variables are positive? (3a^1/2b^1/3)^2 The carrot symbol represents exponents. It is a^1/2 and b^1/3, just so you know. Square each term in the parenthesis. 3^2 = 9 (a^1/2)^2 = a (b^1/3)^2 = b^2/3 Put it

55. ## chem

If an ideal gas is allowed to expand into a vacuum, this means that the external pressure is 0. This doesn't affect the internal pressure though, correct? For example: I have a problem in which one mole of an ideal gas at 300. K and at a volume of 10.0 L

56. ## organic chemistry

one mole of triphenylmeethanol lowers the freezing point of 1000g of 100% sulfuric acid twice as much as one mole of methanol. How do you account for this observation? the only thing I can think of that would explain that would be intermolecular forces.

57. ## Calculus-Limits

Okay, i posted this question yesterday, however, I did not really understand the answer I received. If your the one who answered my question, could you please elaborate. If not, could you try to answer this tough, for me, question. Thanks a lot. lim x-->0

58. ## chemistry - kinetics

The activation energy for the isomerization of methyl isonitrile is 160 kJ/mol. Calculate the fraction of methyl isonitrile molecules that have an energy of 160 or greater at 500 K? 510 K? What is the ratio of the fraction at 510K to that at 500K? I missed

59. ## science

what determine's the direction that Halley's comet points? The tail points away from the sun.

60. ## English/GuruBlue

I needed to write an essay on how Hamlet is a hypocrite and my three points were that he doesn't obey his father right away, he says he loves his mother but treats her badly, and he says he loves Ophelia but he is the cause of her madness. But now, my

61. ## Econ MC

Two firms, A and B, each currently dump 50 tons of chemicals into the local river. The government has decided to reduce the pollution and from now on will require a pollution permit for each ton of pollution dumped into the river. The government gives each

62. ## Chemistry

Would a substance that does not form hydrogen bonds have a high or low surface tension? What about vapor pressure, specific heat,heat of vaporization or boiling point? It requires extra energy to break hydrogen bonds so a substance that does not form H

63. ## ELa

wat is a noun after all these years i have forgotten Thank you for using the Jiskha Homework Help Forum. A good dictionary will always help you and here is what my Online Dictionary says for noun: Date: 14th century : any member of a class of words that

64. ## English

What type of sentence is this? On July 4, 1976, the nation’s bicentennial, 10,741 American flags were flown over the U.S. Capitol, the largest number ever flown there in one day. It's a simple sentence with two appositives. Can you please help me with my

65. ## earthworms

what is a pharynx? Check this site for a diagram of an earthworm, including the pharynx. http://www.infovisual.info/02/006_en.html

66. ## Organic Chemistry

What is the product formed from a reaction of butanal and sodium hydroxide? cyclopentanone and sodium hydroxide? acetophenone and sodium hydroxide? Thanks. You want to look up information about the Aldol condensation.

67. ## Chem

Calculate the pH of a solution composed of 155mL of 0.1 M acetic acid and 45 g of sodium acetate. The pKa of acetic acid is 4.76. MY ANSWER: pH = 4.76 + log(3.53M/0.1M) pH = 6.31

68. ## Chemistry

Would CH4 dissolve in water? Why or why not? CH4 is non-polar. H2O is polar. CH4 is not soluble in water.

69. ## physic

What does “seven earths" as mentioned in surah at-Talaq actually mean?. what is each cointing on earth? please give detail answer.

70. ## MATH

A plane flying with a constant speed of 24 km/min passes over a ground radar station at an altitude of 4 km and climbs at an angle of 45 degrees. At what rate, in km/min, is the distance from the plane to the radar station increasing 2 minutes later? Rate

71. ## MATH

A spherical snowball is melting in such a way that its diameter is decreasing at rate of 0.2 cm/min. At what rate is the volume of the snowball decreasing when the diameter is 8 cm? (Note the answer is a positive number). Rate =? d ?

72. ## Physics

In a game of pool the cue ball strikes another ball of the same mass and initially at rest. After the collision the cue ball moves at 3.50 m/s along a line making an angle of 22 degrees with its original direction of motion. and the second ball had a speed

73. ## Chemistry

What do strong electrolytes, weak electrolytes, and nonelectrolytes have in common? Severl things, I am sure, but one that comes to mind is that all are composed of cations and anions. That may not fit into your situation, however.

74. ## math/statistics

Could anyone explaint to me what role the Binomial Theory plays in statistics and probability? Using statistics, we can make statements about a population based on sample data. Probability helps us make those statements. The binomial theory can be used to

75. ## Chemistry

How does dissolving a solute affect the boiling point or freezing point of the solution? What about the solution's vapor pressure? Read about Raoult's Law, freezing point depression and boiling point elevation.