Saturday

April 25, 2015

April 25, 2015

Total # Posts: 513

**Propagation of error and sig. figs**

I'm really embarrassed to ask this! I knew how to do it before but I forgot after 2 years. I remember learning it for analytical chemistry :( So a basic problem: What is x= a+b+c? given that: a= 100.7 +/- 0.05 b= 0.61 +/- 0.005 c=226 +/- 0.5 OK. My question is the ...
*January 22, 2010*

**english**

What nursery rhyme character was a "wise galoshes wearing feline" answer has 12 letters.
*January 20, 2010*

**4th grade**

What is matter made up of?
*January 17, 2010*

**science**

Does lighting occur when charges jump between the thunder cloud and the positive ground as a discharge?
*January 16, 2010*

**Science**

Is discharge of static electricity from a huge cloud called a thundercloud?
*January 16, 2010*

**4th grade**

Is all matter made up of tiny particles too small to see
*January 16, 2010*

**math**

if the altitude of a triangle is doubled and the base is multiplied by 3,what is the effect on the area?
*January 12, 2010*

**accounting**

You are provided with the following transactions that took place during a recent fiscal year. Complete the table indicating whether each item (1) should be reported as an operating (O) activity, investing (I) activity, financing (F) activity, or as a noncash (NC) transaction ...
*December 7, 2009*

**Calculus**

Suppose a cylindrical can is manufactured with radius r. The manufacturing process makes the length r imprecise; r can be off by ±0.03 cm. The manufacturing process makes the height of the can precisely equal to three times the radius r (including any error in r, but ...
*December 4, 2009*

**algebra**

72 students is 90% of how many students
*November 17, 2009*

**math**

Find the percent using the percent proportion 75 rolls is what percent of 1000 rolls
*November 17, 2009*

**math**

Identify the percent,whole , and part in the following 30% of 730 is 219 do not solve for any unknowns Percent= Whole= Part=
*November 17, 2009*

**math**

A michigan orchard made 11,491lb of taffy apples with approximately 1lb of taffy mixture for each 76.7 pounds of apples. To the nearest tenth of a pound, how many pounds of apples and how many pounds of taffy were used
*November 16, 2009*

**MO theory regarding heteronuclear diatomic molecul**

Hi all I am having trouble finding the MO order for heteronuclear diatomic molecules: In my textbook, heteronuclear order is listed as: 1o 2o 3o 4o 1pi 5o 2pi 6o where o = sigma When I first saw it, I was confused; how can the above be correct? If one were to calculate bond ...
*November 11, 2009*

**11th grade chemistry**

how many molecules do you have in 64g of CO?
*November 11, 2009*

**Term symbols for ground states**

Dr Bob, Thank you so much!! You have taught me something in mere minutes that my professor failed to do in a single lecture. And thank you again for the web site. I had no idea such a site existed! I wish there was a karma/rep system :) thanks again
*November 5, 2009*

**Term symbols for ground states**

OHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH. if it was 8e- in d orbitals (5 of em) it would be +2 +1 0 -1 -2 for up spin , then +2 +1 and 0 for down spin! therefore, total is 3 and L=3!!!! I hope this is correct!
*November 5, 2009*

**Term symbols for ground states**

Thank you Dr Bob. Yes, I am seriously confusing myself haha As far as the 4d8 is concerned, I was referring to Ni2+ it has 8 electrons it occupies 2, 1, 0, -1, -2 so would that make L = 0 which is S? Sorry for the confusion. I greatly appreciate you staying and helping me ...
*November 5, 2009*

**Term symbols for ground states**

what about Nb2+ then? it has 8 electrons it occupies 2, 1, 0, -1, -2 so would that make L = 0 which is S?
*November 5, 2009*

**Term symbols for ground states**

But for Nb2+ where it is 4d^3 Shouldn't L be D instead of F? Like p^2 in carbon, L = P And in s^2, L = S ------ Or am I going about this the wrong way?
*November 5, 2009*

**Term symbols for ground states**

You are correct DrBob. Error on my part.
*November 5, 2009*

**Term symbols for ground states**

I have having difficulty understanding where L comes from in term symbol notation For Carbon, e- configuration is 1s^2 2s^2 2p^2 p corresponds to l=1 overall spin is 3/2 since cell is less than half-full, J=S=3/2 so term symbol is 4 P (3/2) this i understand where P came from...
*November 5, 2009*

**Quantum mechanics, eigenvalues, eigenfunctions**

I'll also like to thank Dr. Physics for helping me last time :)
*October 22, 2009*

**Quantum mechanics, eigenvalues, eigenfunctions**

What exactly is an eigenvalue? "To be an eigenfunction, the operator has to reproduce the function with some multiplicative constant." Is the eigenvalue the multiplicative constant -or- is it the m constant and the function? Many thanks.
*October 22, 2009*

**statistics**

A certain airplane has two independent alternators to provide electrical power. The probability that a given alternator will fail on a 1-hour fight is .02. What is the probability that (a) both will fail? (b) Neither will fail? (c) One or the other will fail? Show all steps ...
*October 9, 2009*

**Quantum mechanics, eigenfunctions!**

Thank you! I thought I was going crazy because I wasn't able to an eigenfunction since 1st deriv. would be = cos(x)*e^(ax) + a*sin(x)*e^(ax) which is definitely not an eigenfunction of the operator.
*October 8, 2009*

**Quantum mechanics, eigenfunctions!**

Determine if the function sin(x)*e^(ax) where a=constant is an eigenfunction of the operators d/dx and d^2/(dx)^2 Okay. My understanding is that you use the operator and perform its "thing" on the function. In this case, you will have to find the 1st derivative of ...
*October 8, 2009*

**social studies**

what imapct did the enstablishment of french and dutch coloies in north america have on native americans?
*September 29, 2009*

**6th grade**

How did Canadian Inuits make their decisions. Also did the have a leader or chief and how were they chosen
*September 26, 2009*

**biology**

identify what all organic compounds have in common,and list the four principal classes of or organic compounds
*September 23, 2009*

**Physics AP C**

Two trains, each having a speed of 22 km/h, are headed at each other on the same straight track. A bird that can fly 60 km/h flies off the front of one train when they are 70 km apart and heads directly for the other train. On reaching the other train it flies directly back to...
*August 26, 2009*

**Fundamental Cornerstones of Managerial accounting**

Green Enterprises produces small engines for lawn mowers. during the year, 110,000 engines were produced. The actual labor used was 60,000 hours at $9.50 per hour. Green has the following labor standard: 0.5 hour at $10 1. compute the labor rate variance. 2. compute the labor ...
*July 30, 2009*

**Chemistry**

Write the net ionic equation for silver nitrate and sodium chloride. I only know how to do it when it deals with elements, not compound.
*July 23, 2009*

**math**

x*y=50 x/y=2 10*5=50 10/5=2
*July 19, 2009*

**math**

A right triangle has a hypotenuse of length 3.00 m, and one of its angles is 30.0°. What are the lengths of (a) the side opposite the 30.0° angle and (b) the side adjacent to the 30.0° angle?
*July 19, 2009*

**math**

A painting measuring 100cm by 55cm is to be framed with a matte border of uniform width surrounding the painting. the combined area of the picture and the matte is 9796cm^2. How wide is the matte border?
*July 12, 2009*

**math**

A rectangular field is to be enclosed by a fence. Two fences parallel to one side of the field divide the field into three rectangular fields. If 2400m of fence are available find the dimensions giving the max area.
*July 12, 2009*

**math**

solve for x 3x^2-18x=0
*July 12, 2009*

**grade 11 math**

a uniform-width boardwalk is built around the inside edge of a rectangular parkland that is 10m by 15 m. if the boardwalk takes up 20% of the lot, how wide is the boardwalk to the nearest centimetre?
*July 7, 2009*

**Physical Science**

what grade is this
*May 22, 2009*

**Math**

Today's HW, due tomorrow, I'm lost, please help. 1. 5y - 7x = 10 2. 2y = 10 - 2 (x - 3) 3. y = 2x + 1/2 (3x + 1) + 1/4 (2x + 8)
*May 4, 2009*

**Physics**

If two pith balls - one which is neutral and another which has a charge of -9.6 uC (micro-Coulombs) - are touched together, how many extra electrons will each ball have?
*April 8, 2009*

**CHEM HELP**

Which of the following is NOT true of colligative properties? Colligative properties are... a) dependent on the molar mass of the solute. b) dependent on the mass of solute present. c) responsible for lowering the vapor pressure of a solution versus the vapor pressure of the ...
*April 2, 2009*

**math: factoring**

how would i factor this 2x^2(p + q^3) - (p + q^3)
*March 20, 2009*

**MATH**

I NEED TO FIND WHAT 33333+12=
*March 9, 2009*

**MATH**

END 1045PM ELAPES TIME 12HR 35MIN FIEN WHEN STARTED
*March 9, 2009*

**college chemistry**

I got 1)Potassium persulfate 2)persulfate ion 3)Sodium thiosufate 4)thiosulfate ion
*February 25, 2009*

**college chemistry**

How do I name the following compounds; K2S2O8, S2O8{-2}, Na2S2O3 and S2O3{-2}
*February 25, 2009*

**Chemistry**

The mol mass calculated would be higher than expected. but when we are measuring the pure cyclohexane's freezing point, this wouldn't matter right?? The freezing point would be the same no matter what the volume of solvent.
*February 25, 2009*

**mathematics**

For each of the following state the axiom, definition illutrated. All elements written are whole numbers. v-e= s since e< v and s + e = v
*January 25, 2009*

**Social studies**

what are aboriginal rights ?
*January 22, 2009*

**Social studies**

what are aboriginal rights ?
*January 22, 2009*

**math**

please explain to me how to dived this 57/550
*January 12, 2009*

**arithmetic**

619
*January 10, 2009*

**arithmetic**

4863
*January 10, 2009*

**arithmetic**

50divied483
*January 10, 2009*

**TRivia**

Who said,We may have disagreement, but let some other country step on our tail and see how quickly American unite. It is a Western movie star.
*January 5, 2009*

**Mircoeconomics**

Figure 3-1 ____ 2. Refer to Figure 3-1. Assume that Cliff and Paul were both producing wheat and corn, and each were dividing their time equally between the two. Then they decide to specialize in the product they have a comparative advantage in. As a result, total production ...
*December 5, 2008*

**math**

22 divied 2
*December 1, 2008*

**chemistry**

Well i believe it is bc H20 needs alot of energy to bc a gas bc of the molecular bonds on it, while CO2 requires less energy to become a gas so that is why it becomes a gas at room temp
*November 25, 2008*

**french**

im trying to say I, and im a boy? so its il?
*November 17, 2008*

**french**

can someone help me edit this? Pour sa nouvelle chambre, il (elle?) veut changer les meubles et la couleur des murs. Aussi, il (elle?) veut organiser sa grande collection de livres des animaux ty
*November 17, 2008*

**PHYSICS**

A spinning wheel on a fireworks display is initially rotating in a counterclockwise direction. The wheel has an angular acceleration of -3.80 rad/s2. Because of this acceleration, the angular velocity of the wheel changes from its initial value to a final value of -21.0 rad/s...
*November 14, 2008*

**science**

in the year 1971. astronaut alan shepard hit a golf ball whila on the surfase of the moon. it became the longest golf shot in history alan shepard was able to hit his recod golf shot because A.the moon dods not have any gravity B.THE GRAVITY OF THE MOON IS WEAKER THAN THE ...
*November 8, 2008*

**science**

some traits in animals are in herited from parents to off spring other traits are learned or result from the influense of the animal's environment identify the trait that results from the influense of the animal's environmet A.many species of insects lay thousands of ...
*November 8, 2008*

**science**

IN SCIENSE CLASS STUDENTS ARE TO FOMULATE A TESTABLE HYPOTHESIS FUOR OF THEYR HYPOTHESIS ARE GEVEN BELOW. WHISH OF THE HYPOTHESIS WOULD BE MOST EASILY TESD BY A FIFTH GRADER .A WATHER AND LAND ABSORB THE SUN,S ENERGY AT DIFFERENT RATES.B. THE MONACH BUTTERFLY'S ENVERONMENT...
*November 8, 2008*

**science**

in order to smell the fumes in a safe manner you should A,hold the item to you nose and sniff quickly B.gently wava the fumes toward you nose and sniff very lightly.C,quickly wave the fumes toward you nose and sniff deeply,D.ASK YOUR TEACHER TO SNIFF THE FUMES FOR YOU
*November 8, 2008*

**science**

solar ligth ,heat ,geothermal solar ligth electrical, solar heat geothermal,solar light heat
*November 8, 2008*

**science**

what forms of energy are provided by the sun
*November 8, 2008*

**science**

whish of the following plantstraits not inherited gras turns darker when sprinkled whid nitrgen B.arosebush has thorns C.maple tree leaves die in the fall D.a cactus stores water
*November 8, 2008*

**algebra**

How do I define a variable and write an inequality to model the following situation? The temperature in a refrigerated truck must be kept at or below 38Deg F
*November 5, 2008*

**science**

The force of attraction between two objects________decreases or increases if you increase the amount of mass or substance in the bodies. The force of attraction between two objexts___decreases or increases if you increase the distance between them?
*October 13, 2008*

**Math**

What is the GCM of 10 and 25.
*September 17, 2008*

**Math**

What is the LCM of 25 and 10
*September 17, 2008*

**human services in the united states**

week six prevention example paper
*September 7, 2008*

**Axia College**

i have been a axia university of phoenix for a year now and its a very well known college and very creditable
*August 7, 2008*

**Sociology Multiple choice**

For question number 2. The answer is D right?
*June 12, 2008*

**Social Studies**

What was the saying that the colonists cried to protest British tariffs on goods?
*June 3, 2008*

**math**

Factor the trinomial c^2+5c+6
*May 2, 2008*

**calculating infinity**

1) I get it, except for lim (-1)^(n) = ? n-> +infinity is infinity even or odd? This is important because the result determines wheter the series that i was given is convergent or divergent. 2) in another excercise I encauntered the following problem: is the following ...
*April 16, 2008*

**calculating infinity**

can someone tell me wich one of the two awnsers for these two limits is correct? lim (-1)^(n) = 1 or -1 n-> +infinity lim (-1)^(n) = 1 or -1 n-> -infinity Thanks in advance.
*April 16, 2008*

**Biology**

sorry a few more questions why can DNA form fibres that allow it to seprate from RNA while RNA cant form such fibres? also, when treated with DNAse, I know DNA viscosity reduces because its cut up into smaller pieces. but on a graph of viscosity vs time, I have this ...
*April 9, 2008*

**Biology**

What does base do to DNA when it is added to it?
*April 9, 2008*

**Physics**

how do i find gravitational potential energy without being given the height?
*March 26, 2008*

**Physics**

A boy weighing 40kg runs at 8.0m/s grabs a rope and swings of level ground. What maximum height does the child reach? How do I solve this?? it is under the conservation of energy section of work, power and energy. any help would be great! thanks
*March 26, 2008*

**algebra**

x+1/x=-7/x-12
*March 2, 2008*

**Math**

find the area and permiter of trapazoides?
*February 19, 2008*

**algebra**

polynomial subtraction a-a2-a-6/2(a-3) a-a(squared)-a-6 divided by 2(a-3)
*February 7, 2008*

**spanish**

Can someone please check this for me? How long has it been since the following people have done the following things? Write the answers using the expression hacer + time. 1) Santi y Silvina: no estar casados / un año Your response: Hace un año que Santi y Silvina...
*February 5, 2008*

**Physics**

I NEED HELP.... I look in my text for an inverse square law and i get G=M1M2/d^2, But im not given a two masses. The repusive force between two ceramic magnets was measured and found to depend on distance, as given in the table. Separation, d (mm) Force,F (N) 10 3.93 12 0.40 ...
*October 31, 2007*

**pre-calc**

(8y2+3y-7)(3y+4)
*October 17, 2007*

**Organic chemistry: dehydrohalogenation**

P.S. I understand the mechanisms of E1, E2, and dehydrohalogenation. I just don't know how to find out whether an alkyl halide undergoing dehydrohalogenation will follow an E1 or an E2 reaction.
*October 10, 2007*

**Organic chemistry: dehydrohalogenation**

Hello. I know you guys don't do organic chemistry but because I got so much help from you guys in general chemistry, I was wondering if you guys can help me out again. :P Here's my question. In dehydrohalogenation, how do you know whether a reaction is E1 or E2? My ...
*October 10, 2007*

**math**

What is the probability of a die not coming up six, six times in a row? How do I solve that problem?
*October 1, 2007*

**Math**

Can you show me how to solve this problem? You have a die, what is the probability you will not get a six, six times in a row?
*October 1, 2007*

**general math**

I have 20 puzzle tables (1,2,3,…,20) that contain of 10 rows (1,2,3,…,10) each. There are numbers 1,2,3,4,… in each of every tables, which has a unique position to every rows. I am just wondering if you can help me how to find the relations between them, so the ...
*September 25, 2007*

**Calculus**

OK trying again. For what (numerical) of the constant "c" is the function f(x)= {x^2-cx if x is greater than -1 {cx^3+x if x is less than or equal to -1 continuous on (- infinity, +infinity)?(Justify answer!)
*September 16, 2007*

**Calculus**

For some reason the answer to this question is alluding me, Im sure its probbly something simple im just over looking. For what (numerical) value of the constant "c" is the function continous on (-?,?)?( Justify Answer) f(x)= x^2-cx if x>-1 cx^2+x if x?-1
*September 15, 2007*

**computer graphics**

You purchase the latest "must have" computer video game from the store. The game has fantastic graphics but it runs rather slow on your computer. What must you do to increase the performance of the game? 1. Install a GVA adapter that has more ROM. 2. Install a video ...
*June 13, 2007*