chemistry! URGENT
61,546 results, page 21

MA
a) find the equation of AB, the perpindicular bisector of the line joining the points P(3,1) and Q(1,9) (line AB intersects the point at midway of PQ) b) C is the centre of a circle passing through P and Q. given that QC is parralel to the yaxis, determine theequation of the ... 
Microeconomics help please (urgent)
True or False? Explain your reasoning. a. The shortrun average total cost can never be less than the longrun average total cost. b. The shortrun average variable cost can never be less than the longrun average total cost. c. In the long run, choosing a higher level of ... 
Physics  URGENT
A small block of mass 5 kg initially rests on a track at the bottom of a circular, vertical looptheloop, which has a radius of 0.8 m. The surface contact between the block and the loop is frictionless. A bullet of mass 0.7 kg strikes the block horizontally with initial speed... 
MATH URGENT!!!!
With the given model: h=0.045d^2+2d where h is the height of the ball from the ground(in yards) and d is the horizontal distance of the ball(in yards) from its starting point. A.)Pat is standing on the 17yard line when the football passes over his head. How high up is the ... 
UNIT FRACTIONS URGENT~!
I have been stuck on this for hours and feel completely stupid, could someone help? Read the story problem given below. Identify what unit conversions must be made and show your unit fractions in making the conversions. Make the required conversions and round results ... 
ALGEBRA! URGENT.
1. What data are represented by the stemandleaf plot below? 3  7 8 9 4  1 3 7 5  2 4 Key: 4  1 means 41 a. 37, 38, 39, 41, 43, 47, 52, 54 b. 73, 83, 93, 14, 34, 74, 25, 45 c. 7, 8, 9, 1, 3, 7, 2, 4 d. 37, 38, 39, 14, 34, 74, 25, 45 2. Find the mode and the median of the ... 
Urgent =Math
17. Tell whether this survey describes a good sample and if so, name the method of sampling used. Every sixth person leaving a restaurant is surveyed to determine their favorite food from the menu. yes, random******** yes, systematic yes, stratified not a good sample 18.Tell ... 
maths urgent
a) Forming the smallest six digit number with different digits. Reverse the number and add the sum of the two numbers. b)Forming the smallest five digit number with different digits. Reverse the number and add the sum of the two numbers. 
chemistry help
this isnt exactly a chemistry question, but i am doing chemistry homework with my calculator. and i want to know if someone can tell me how can i cube something with this calculator? TI30X IIS? i wanted to post a pic but i cant post sites. i have this calculator can you tell ... 
VERY URGENT MATH~!!!!!!!!
1. 2(x – 3) = 2x (1 point) one solution no solutions infinitely many solutions 2. 3(y – 3) = 2y – 9 + y (1 point) one solution no solutions infinitely many solutions 3. 10x – 2 – 6x = 3x – 2 + x (1 point) one solution no solutions infinitely many solutions 4. 4(x... 
Chemistry
I need to perform a chemical demonstration on thermochemistry or kinetics or colligative properties for chemistry class. However I cannot have demonstrations involving fire. 
Chemistry
Can anyone help me with some topics to write about on what chemistry has to do with mechanical engineering. Anyone's help would be appreciated because I really need to finish this 10 page research paper. 
Calculus (urgent!!)
A particle moves with its position given by x=cos(2t) and y=sin(t), where positions are given in feet from the origin and time t is in seconds. A)Find the speed of the particle. Speed = ____________ (include units) B)Find the first positive time when the particle comes to a ... 
Chemistry
How does understanding chemistry help us in todays world 
Chemistry
Sorry, just asking a question on chemistry. 
CHEMISTRY
WHAT RELATION DOES CHEMISTRY HAVE TO ART? 
chemistry
Does Chemistry have anything to do with meteorology? 
chemistry
how does space exploration involve chemistry 
AP CHEMISTRY
i added info in the last question in AP CHEMISTRY 
chemistry
what is chromatography? Its history,purpose in chemistry. 
Chemistry
How do I write a blog for my chemistry project? 
chemistry
which topics are under periodic chemistry II? 
chemistry
what topics are under periodic chemistry? 
Chemistry
What are the parts of a calorimeter used in chemistry? 
ap chemistry
how does chemistry apply to everday life? 
Calculus Help Please Urgent!!!
A piece of wire 14 m long is cut into two pieces. One piece is bent into a square and the other is bent into an equilateral triangle. (a) How much wire should be used for the square in order to maximize the total area? 14 m this one I got right (b) How much wire should be used... 
Algebra 1 Urgent
Part A: Sam rented a boat at $225 for 2 days. If he rents the same boat for 5 days, he has to pay a total rent of $480. Write an equation in the standard form to represent the total rent (y) that Sam has to pay for renting the boat for x days. (4 points) Part B: Write the ... 
maths
a) find the equation of AB, the perpindicular bisector of the line joining the points P(3,1) and Q(1,9) (line AB intersects the point at midway of PQ) b) C is the centre of a circle passing through P and Q. given that QC is parralel to the yaxis, determine theequation of the ... 
As chemistry
A SAMPLE OF ANTIMONY, Ar=121.8, WAS ANALYSED AND WAS FOUND TO CONSIST OF 60% OF 121Sb AND ONE OTHER ISOTOPE. DETERMINE THE MASS NUMBER OF THE OTHER ISOTOPE IN THE SAMPLE OF ANTIMONY. please help I'm really stuck, Chemistry  bobpursley Saturday, September 30, 2017 at 10:41am ... 
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 those who learn none... 
Math
In a class of 100 students, 40 offer Biology and 10 offer Chemistry and Biology .10 offer Physics and Chemistry , and 30 offer Physic and Biology . Each student offer at least one of the three subjects. The number of students who offer Biology is equal to those who offer ... 
English urgent please:)
I wrote the thesis but wat do i make the conclusion be...:( This is my thesis: Aldous Huxley's Brave NEw World and Emily Bronte's, "wuthring heights" describe a major struggle of being an individual again society . in Aldous Huxley's novel "Brave New World, the main story ... 
Calculus Help Please Urgent!!!
a) Estimate the area under the graph of f(x)=7+4x^2 from x=1 to x=2 using three rectangles and right endpoints. R3= ??? Then improve your estimate by using six rectangles. R6= ??? Sketch the curve and the approximating rectangles for R3 and R6? b) Repeat part (a) using left ... 
math URGENT PLEASE HELP
can you please explain this question to me for part b i get t=0.7 by trial and error and 0.6 percent of the population but im sure theres a more exact way to do it (a) A chemical process produces NaCI at the rate 3.Jtgrams per minute. (i) What is the rate of production 4 ... 
Math
A bag contains 2 white marbles and 7 purple marbles. Two marbles are drawn at random. One marble is drawn and not replaced. Then a second marble is drawn. A) What is the probability of selecting a purple marble and then a white marble? B) What is the probability of selecting ... 
Physics Urgent please help
A small sphere of mass m and charge +q with zero velocity falls under the influence of gravity (acceleration = g from height h onto an infinite uniformly charged plane with positive charge density sigma as shown below. What will the velocity of the sphere be when it hits the ... 
Physics Urgent please help
A small sphere of mass m and charge +q with zero velocity falls under the influence of gravity (acceleration = g from height h onto an infinite uniformly charged plane with positive charge density sigma as shown below. What will the velocity of the sphere be when it hits the ... 
economics. urgent
Assuming that shoes have a world price of US$60 a pair, that the EU has a 45% ad valorem import duty on footwear which applies to all types of footwear and an Italian company is proposing a project to substitute 150,000 pairs of imported shoes by domestically produced shoes. ... 
AP Chemistry
Hey I have the AP Chem test coming up and i was wondering where I could find the answer key to some of the AP Chemistry tests like 1994, 1999, and 2002 MC and FR 
Chemistry
Why does the reaction of 2bromo2methylbutane and ethanolic solution of silver nitrate interfered by the presence of water in the sodium iodide in acetone reagent? (Substitution chemistry) Thanks for any help!! 
Chemistry
Use the data in Table 15.3 (in the book Chemistry after Raymond Chang) to calculate the equilibrium constant for the following reaction: HCOOH(aq) + OH(aq)= HCOO(aq) + H2O(l) 
Chemistry
Hello. On the homework for my middle school chemistry class, one of the questions asks me to identify "the four classifications of substances". I am having difficulties with this problem. 
literature
plz to anyone who has finished the lit book with 7 tests answer back need help. with exms like pair of silk stockings, pauls case,goodman brown, call of the wild PLZZZZZZZ help me it has been 15yrs http://www.trainingner.com/doesanyonehavetheanswerstothepennfoster... 
ALG 2! plz help urgent!!
1.)Four times a certain number is the same as the number increased by 78. Find the number. 2.)A blue bike is $14 less than a red bike. The sum of their prices is $300. How much is the red bike? 3.)Alex is six years older than his sister, Emma. The sum of their ages is 32. How ... 
chemistry
Posted by Bret on Friday, March 16, 2007 at 10:44am. what is the oxidation number for nitrogen in the following? NH3 NO2 1 N2 NO2Cl N2H4 For Further Reading chemistry  bobpursley, Friday, March 16, 2007 at 11:26am We will be happy to critique your thinking or work. chemistry... 
chem  Urgent, please help
0.702g arsenic combines with 0.225g of oxygen to make an oxide of arsenic. When heated this produces a gas with a volume of 52cm3. How do i work out the molecular formula of the oxide when its in a gaseous state? The weight ratio will tell you, after dividing by atomic weights... 
I.Q QUESTION (Urgent)
Can u help me out on the question below please. Would you rather a crocodile attack you or an alligator? I'd rather have it attack an alligator. Definitely certain crocs are more dangerous. http://www.bugbog.com/travel_safety/dangerous_animals/crocodile_attacks.html Just say ... 
Physics (please help!!!!)
Sorry to repost this, again, but I still don't understand. Newton’s Law of Gravity specifies the magnitude of the interaction force between two point masses, m1 and m2, separated by the distance r as F(r) = Gm1m2/r^2. The gravitational constant G can be determined by ... 
Physics (please help!!!!)
Sorry to repost this, again, but I still don't understand. Newton’s Law of Gravity specifies the magnitude of the interaction force between two point masses, m1 and m2, separated by the distance r as F(r) = Gm1m2/r^2. The gravitational constant G can be determined by ... 
science URGENT so need help
PLS HELP ASAP True or False 1. If a 40 kg person is accelerating at 10 m/s2, then the magnitude of the force acting on him or her is 400 N. (1 point) true false Multiple Choice 2. How much force is needed to make a 60 kg object accelerate at a rate of 2.0 m/s2? (1 point) 62 N ... 
accounting ..urgent pls
PLEASE HELP ME AND YOU ARE ALL BRIGHT AND I NEED YOUR HELP FOR SOLVING THIS PROBLEM. PROBLEM 1: CARE p’ship at December 31 had cash amounting to $20,000, noncash assets $100,000, liabilities $55,000, and the following capital balances: Cassandra $45,000 and Penelope $20,000... 
math(urgent)
9.A 10%,100day note was dated 20 september 1992.the maturity value of the note was $3083.33.If the note was discounted on 17 november 1992 at 12%,FIND i) the maturity date of the note = 29 december 1992 ii)the face value of the note $3083.33 = (1+0.1(100/360) = 1.0278 = 3083.... 
physics, help! urgent!
A positive point charge q = +2.50 nC is located at x = 1.20 m and a negative charge of ƒ{2q = ƒ{5.00 nC is located at the origin. (a) Sketch the electric potential verses x for points on the xaxis in the range 1.50 m < x < 1.50 m. (b) Find a symbolic expression for ... 
English (Urgent)
In John Cheever's story reunion, what do the restaurants symbolize. Why does Charlie call hi father daddy at the end of the story? Examine the first and last sentences of the story. What is common and why? How do you interpret the ending of the story? Does Charlie accept of ... 
scienceplz help, this is urgent!plz!
we did a lab on chemical change, where we had to see how a chemical change affcts mass. so we measure the mass of 20ml of copper solution, and 2cm(cubed) of steel wool, and then we mixed them into a flask. soon the steel wool turned rusy, and broke apart. and the duofilm(which... 
scienceplz help, this is urgent!plz!
we did a lab on chemical change, where we had to see how a chemical change affcts mass. so we measure the mass of 20ml of copper solution, and 2cm(cubed) of steel wool, and then we mixed them into a flask. soon the steel wool turned rusy, and broke apart. and the duofilm(which... 
sociology
hi people actually i need 2 do a project on sociology for 20 marks n i cant decide which on a topic ca u all plz help n v also need 2 have a survey or 3040 interviews plz plz plz plz help its urgent It would really help us teachers if you would write in standard English so we... 
Physics urgent help please
A rectangular coil 60mm × 40mm with 25 turns is positioned with its longer sides parallel to a long straight vertical wire carrying a current of 6.8A. The coil is placed so that its long sides and the vertical wire are in the same vertical plane, with the wire 40mm away from ... 
Urgent Chem help.plz
The crystal structure of lithium sulfide (Li2S) is pictured here. (Intro 1 figure) The edge length of the unit cell is 5.88*10^2^2 pm. i guess it is FCC ( face cenred cubic) 1 What are the coordination numbers of and Li^+ and S^2 in the lithium sulfide crystal shown? Enter ... 
chemistry
What are some applications of Nuclear Chemistry in Medicine? So far I've found  Xrays  Radioactive tracers  Gamma radiation can be used to treat cancer and other diseases 
Chemistry
Could someone please direct me to a website that explains why acidbase titration is a useful technique in chemistry. Or offer your own opinions. Thanks ahead of time for any input! 
Chemistry
Please helpI need to give at least three examples of how heat, solutions,equillibrium, nuclear and organic chemistry are interrelated. Any help would be greatly appreciatedI'm desperate Thank you 
chemistry
Can someone help me with Chemistry Homework Due Tomorrow, Its about the Electrolysis of Hydrochloric Acid Practical we did and I Have to write a summary and I don't get what we did Y10 GCSE Higher Tier 
Chemistry
A principle of green chemistry is that the energy requirement of industrial processes should have minimal environmental impact. How can the use of catalysts lead to "greener" technology? 
Chemistry
I am having trouble on a chemistry question for my study guide I have researched it and can't get an answer I understand can someone please help me? Describe what happened when an Ag+ combined with Na2CO3. What does this indicate? 
Physics URGENT!!!
A massless spring of constant k =84.8 N/m is fixed on the left side of a level track. A block of mass m = 0.5 kg is pressed against the spring and compresses it a distance d, as in the figure below. The block (initially at rest) is then released and travels toward a circular ... 
Physics URGENT!!!
: A massless spring of constant k =84.8 N/m is fixed on the left side of a level track. A block of mass m = 0.5 kg is pressed against the spring and compresses it a distance d, as in the figure below. The block (initially at rest) is then released and travels toward a circular... 
EnglishUrgent
I have to find the subjects and verbs in all these sentences, please let me know if I did it correctly. Thank you. A guy whom I work with has a theory about college students. (Verb=work, has) (Subject=guy, theory) He believes that students' majors reflect their personalities... 
Chemistry
The population of San Francisco is 750,000 in an area of 49 square miles. What is the population density in San Francisco? Express your answer in people per acre. ( 1mi(squared) = 640 acres ) 49 sq mi x (640 acres/1 sq mi) =?? acres. (Note that sq mi cancels leaving acres.) ... 
Art
Thank you very much. I still need you to check a few urgent things, Writeacher. 1)The line is engaged. Would you hold? Would you like to hold the line? Would you like to hang on/hold on? Which are possible? 2)You needn't have bought the milk; there was some already/there was ... 
Foreign languages
Can you please check these sentences, Writeacher? It's urgent. 1) I'd like to get/have my money sorted out ( I need a synonym) before I leave for university. 2) I want the bank to give (issue is possible?) me a credit card. 3) I've tried many times to stop smoking but I have ... 
Chemistry
Assuming that the smallest measurable wavelength in an experiment is 0.330 fm(femtometers), what is the maximum mass of an object traveling at 157 m·s^–1 for which the de Broglie wavelength is observable? mass = ? kg Chemistry  DrBob222, Monday, October 29, 2012 at 12:29am... 
Chemistry
Assuming that the smallest measurable wavelength in an experiment is 0.330 fm(femtometers), what is the maximum mass of an object traveling at 157 m·s^–1 for which the de Broglie wavelength is observable? mass = ? kg Chemistry  DrBob222, Monday, October 29, 2012 at 12:29am... 
Social Studies (URGENT)
During the immigrant experience in the early 1800s U.S. is said to be a "melting pot", and Canada a "mosaic". a.) What do these two terms mean to you? Melting pot describes the blending of cultures into a single nation. Cultural mosaic describes the mix of cultures coexisting ... 
Physics. Urgent
A vertical spring with a spring constant of 450 N/m is mounted on the floor. From directly above the spring, which is unstrained, a 0.30 kg block is dropped from rest. It collides with and sticks to the spring, which is compressed by 3.0 cm in bringing the block to a momentary... 
Chemistry
I'm having alot of trouble in chemistry. Currently were studying chemical equations and reactions. I would like to know if this is a single or double replacement reaction. 2Li + H2O > 2LiOH + H2 
Chemistry
For the reaction below 2 CH3OH(l) + 3 O2(g) 2 CO2(g) + 4 H2O(g) calculate Srxn at 298 K. (Hint: Use a table of thermodynamic data commonly found at the back of chemistry textbooks.) 
Chemistry
Stuck on this because I haven't done chemistry in a while. Can someone guide me through it or help me out? Balance the reductionoxidation chemical equation in base: MnO4 + HSO3 > MnO2 + SO4^ 2 
chemistry
Why does a titrated sample that is fuschia with phenolphthalein turn colorless when the solution is blown into? HINT: Use chemistry and properly balanced chemical equations to support your statement. 
Chemistry
sorry i will rephrase the question. what is the chemistry behind these elements to give them these qualities and make them react the way they do with like water and such. 1)magnesium 2)calcium 3)potassium 4)sodium 
Science URGENT
Hi, I am working on stoichiometry and limiting reactant problems. I have worked through examples in my book and I did them right and can solve for the excess, however there is one problem in the book that has confused me. I don't understand why they identified the limiting ... 
Chemistry(Please help)
What is the pH of a 5.06E2 M aqueous solution of sodium acetate? I know that I would set this up the same way I did for the previous question that I posted. I am just confused on how to find the Ka. I know it is kw/kb but for what compound is what I do not know. Chemistry(... 
urgent physics
A power line carries a current of 110 A at a location where the Earth's magnetic field has a magnitude of 0.37 Gauss (0.37·104 T) and points due north, very nearly parallel to the ground. Find the direction and magnitude of the magnetic force exerted on a 270 m length of the... 
urgent physics..
Adventurous Mary tries a new game: she puts on her rollerblades and throws the ball towards the wall, lets it bounce off, catches it again, throws it right back, and so on. She notices a strange thing: after the second throw, she is unable to catch the ball anymore since the ... 
Physics URGENT!!!!
1.A 75 kg passenger in a van is wearing a seat belt whent he van moving at 15m/s, collides with a conrete wall. The front end of the van collapses 0.50 m as it comes to rest. a) what was the paseenger's kinetic energy before the crash b) What average force did the seat belt ... 
Physics URGENT
Object 1 (mass=6.4 kg) traveling in the +x direction at a speed of 14.01m/s undergoes an inelastic collision with Object 2 (mass=5.10kg) which is at rest. Object two flies off at a speed of 11.94m/s and an angle θ2=49.8 °. The diagram below is just a sketch and is not ... 
ACT Math
Of the 60 students in a school, 24 are currently studying chemistry. Exactly 16 of the girls in the school are not currently studying chemistry. The number of girls in the school is 33. How many boys are currently studying chemistry? Correct answer is 17. How did they get that... 
chemistry
Please, can someone help? Evaluate log 1. This is my work up until I have gotten stuck: log 1 1=10^x I can't find a common base for 1 and 10^x. Wow, my apologies, this is algebra, not chemistry. but actually I think they use it in chemistry too... Take the log base 10 of each ... 
Accounting urgent Edit
The management of Stampfer Inc. asks your help in determining the comparative effects of the FIFO and LIFO inventory cost flow methods. For 2007 the accounting records show these data. Inventory, January 1 (10,000 units) $35,390 Cost of 120,000 units purchased 484,338 Selling ... 
math
In a class of 50 student 28,22,20 of them offer physics,chemistry and biology respectively also,4 of them offer physics and chemistry but not biology,3 offer physic and biology but not chemistry,6 offer biology and chemistry but not physics if 13 of them offer physics only how... 
chemistry
(Reposting because no one was answering chemistry questions) if you have 100mL of 0.1M acetic acid (ka = 1.8x10(5)what is the pH after 10mL NaOH is added? I came up with an answer of 2.895, but i'm not sure if its right. 
math urgent!
You flip a coin 20 times and get tails 15 times. You flip the coin 80 more times. What do you expect to happen to the experimental probability of getting tails as you increase the number of trials? The experimental probability will get closer to 50% The experimental ... 
Math urgent..............help.....
the table below shows the registered Democrats and Rebuplicans in a school Women men Democrates 152 88 Republicans 98 122 a) find the probbility that a randomly selected person from the school is a male republican. b) find the probbility that a randomly selected person from ... 
Physics. Urgent help!!
The relative humidity is 55% on a day when the temperature is 30.0°C. Using the graph below, determine the number of moles of water vapor per cubic meter of air. on the graph, Vapor pressure of water is on the yaxis and temperature on the xaxis 30C cordinates with 4200 Pa ... 
Math
Hi, I need urgent help with these 3 integrals problems ... been stuck on the questions and the deadline is Friday. Thanks a lot ! 1) For the green's theorem, Q: Using Green's theorem, evaluate the line integral F(r).dr counterclockwise around the boundary C of the region R, ... 
English
Could you please check if everything is ok? It's really urgent. 1)The old woman is wearing an elegant black business suit with a white blouse and a whiteandblue striped scarf. 2)The boy in the picture is wearing a black leather jacket with a white shortsleeved shirt under ... 
Trigonometry URGENT!
A group of scientists found a new species of spider in the desert. The body temperature of the spider appears to vary sinusoidal over time. A maximum body temperature of the spider reaches 125° after 15 minutes from the start of the examination. Then, 28 minutes later, the ... 
URGENT MATHS
I got 2 questions and I've been stuck on them for days and its due in 2 days. 1. For a quick way of doing multiplication, you can do: for example: 81 x 89=? First you do 1x9=9 in which case you have to add '0' in front of it to make it 09. Then you add 1 to any of the 8s and ... 
science (URGENT!! CORRECT PLEASE))
(1) in order for an organism to develop specialized tissues the organism must be which of the following A) A Plant B) An Animal C) Unicellular D) Multicellular ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ My answer: D ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ (2) Which foods are lipids found in... 
English
Can you please check these sentences for me. It's really urgent. 1) Our science teachers are enthusiastic about your proposal of holding our first meeting in Italy. 2)However, prior to our meeting, the head of our science department would like to discuss the theme of our ...