Monday
December 22, 2014

Posts by anna


Total # Posts: 2,061

Urgent Chemistry
The Heisenberg Uncertainty Principle: A student is examining a bacterium under the microscope. The E. coli bacterial cell has a mass of mm = 0.100fg\rm fg (where a femtogram, fg\rm fg, is 10−15g\rm 10^{-15}\; g) and is swimming at a velocity of vv = 7.00ìm/s\mu m/...
March 22, 2014

Chemistry
The Heisenberg Uncertainty Principle: A student is examining a bacterium under the microscope. The E. coli bacterial cell has a mass of mm = 0.100fg\rm fg (where a femtogram, fg\rm fg, is 10−15g\rm 10^{-15}\; g) and is swimming at a velocity of vv = 7.00ìm/s\mu m/...
March 21, 2014

Chemistry
The Heisenberg Uncertainty Principle: A student is examining a bacterium under the microscope. The E. coli bacterial cell has a mass of mm = 0.100fg\rm fg (where a femtogram, fg\rm fg, is 10−15g\rm 10^{-15}\; g) and is swimming at a velocity of vv = 7.00ìm/s\mu m/...
March 21, 2014

Trigonometry
Let (7,-3) be a point on the terminal side of theta. Find the exact values of cos of theta, sec of theta and cot of theta?
March 20, 2014

chemistry
in which of the following pairs of compiunds are both members of the pair ionic compounds? a) PI3 and HBr, b) H2S and NCl3, c)LiF and H2O, d)LiI and NiO
March 18, 2014

Basic English
9. Which of the following sentences contains a comma splice? A. Our friend, who travelled from Tennessee, was quite tired when he arrived. B. The kitten climbed the drapes, it couldn't figure out how to get down. C. The cruise ship docked on Oahu, then again on Maui. D. We...
March 18, 2014

chem
which of the following compound contain more than 10 atoms per formula: a)ammonium phosphate, b) aluminium carbonate, C)iron(III) cyanide,
March 17, 2014

Chemistry
Thank you so much. I figured out what I did wrong.
March 16, 2014

Chemistry
This is a problem I got on my Mastering Chemistry homework: Consider the following reaction: H2(g)+I2(g)⇌2HI(g) A reaction mixture at equilibrium at 175 K contains PH2=0.958atm, PI2=0.877atm, and PHI=0.020atm. A second reaction mixture, also at 175 K, contains PH2=PI2= 0...
March 16, 2014

Physics
A man wishes to cross a river from A to B, a distance of 800m. He can row at 8km per hour, in what direction should he head the boat to travel directly from A to B? How long does it take him to reach B? Please show working. Thank You!
March 16, 2014

Psychology
What is the definition for "Practical problems" and "Ethical problems"
March 13, 2014

Math
how much should rod pay for a 10 year annuity that provides month end payments of 1800 at 4.5% compounded quarterly
March 12, 2014

Chemistry Urgent
95.0mL of H2O is initially at room temperature (22.0∘C ). A chilled steel rod at 2.0∘C is placed in the water. If the final temperature of the system is 21.3∘C , what is the mass of the steel bar? Specific heat of water = 4.18 J/g⋅∘C Specific heat...
March 11, 2014

Chemistry Urgent
A calorimeter contains 32.0mL of water at 13.0∘C . When 2.30g of X (a substance with a molar mass of 82.0g/mol is added, it dissolves via the reaction X(s)+H2O(l)¨X(aq) and the temperature of the solution increases to 30.0∘C . Calculate the enthalpy ...
March 11, 2014

chemistry
95.0mLmL of H2O\rm H_2O is initially at room temperature (22.0∘C\rm{} ^{\circ}C). A chilled steel rod at 2.0∘C\rm ^{\circ}C is placed in the water. If the final temperature of the system is 21.3∘C^{\circ}C, what is the mass of the steel bar? Specific heat of ...
March 11, 2014

Chemistry
Consider the following problem: Target: 2NOCl(g) ? N2(g)+ O2(g)+Cl2 (g) ?Hrxn= ? Steps: 1. 1/2 N2(g) + 1/2 O2(g)? NO(g) ?H= 90.3 kJ 2. NO(g) + 1/2 Cl2(g) ? NOCl(g) ?H= -38.6 kJ As you determine the ¥ÄHrxn value for the target equation above, what must be done to step ...
March 9, 2014

chemistry
Calculate the DHof for the following reaction under standard state conditions: 2 Ag2S(s) + 2 H2O(l) ---> 4 Ag(s) + 2 H2S(g) + O2(g) Given the following information: Ag2S(s) ÄHof = -32.6 kJ/mol H2O(l) Ä Hof = -285.83 kJ/mol H2S(g) ÄHof = -20.6 kJ/mol
March 9, 2014

chemistry
Consider the following problem: Target: 2NOCl (g) ¡æ N2 (g) + O2 (g) + Cl2 (g) ¥ÄHrxn= ? Steps: 1. ¨ö N2(g) + ¨ö O2(g) ¡æ NO(g) ¥ÄH= 90.3 kJ 2. NO(g) + ¨ö Cl2(g) ¡æ NOCl(g) ¥Ä H= -38.6 kJ...
March 9, 2014

chemistry
Calculate the DHof for the following reaction under standard state conditions: 2 Ag2S(s) + 2 H2O(l) ---> 4 Ag(s) + 2 H2S(g) + O2(g) Given the following information: Ag2S(s) ÄHof = -32.6 kJ/mol H2O(l) Ä Hof = -285.83 kJ/mol H2S(g) ÄHof = -20.6 kJ/mol
March 9, 2014

math
can you help me With my homework.
March 8, 2014

prealgebra
Caitlin's cylindrical jar holds 525 cubic inches. If the height of the jar is 7 inches what is the approximate diameter?
March 6, 2014

Math
How do you find the derivative of ln(xy)=x+y
March 3, 2014

Geometry/Trig
A plane is flying and show an air speed of 130 mi/h. However, there is a 20 mi/hr crosswind. What is the resulting speed of the plane.
March 3, 2014

trigonomentry
Ada travels from A on a bearing of 60˚ to station B on a distance of 15km.she then leaves to station C 10km away from B due east of station
March 2, 2014

maths
now there is a pool, the height of the pool is 48cm and the width is 2m, now 3 quarters are full, what will be the final answer in litres?
March 2, 2014

Chemistry
How has crude oil changes the country (positive and negative points)
March 1, 2014

Analytical Chemistry
A - 1 B-3 C-2 D-4 E-5 F-6 G-7
February 28, 2014

geometry
Circle the following quadrilateral that does Not have at least one pair of consecutive sides congruent. (A) rhombus (B)kite(C)isosceles trapezoid(D) square Circle the following quadrilateral that may have exactly one pair of consecutive sides of congruent. (A)rhombus (B) kite(...
February 26, 2014

statistics
Construct a 95% confidence interval for the population mean. 5. Airfare A random sample of airfare prices (in dollars) for a one-way ticket airfare between two cities MN. Key: 21|1=211 21 | 1 2 22 | 1 1 1 2 3 5 7 8 23 | 2 3 4 7 7 8 9 9 24 | 2 3 4 8 8 25 | 1 2 6 6 6 6 8 9
February 23, 2014

statistics
Construct a 95% confidence interval for the population mean. 5. Airfare A random sample of airfare prices (in dollars) for a one-way ticket airfare between two cities MN. Key: 21|1=211 21 | 1 2 22 | 1 1 1 2 3 5 7 8 23 | 2 3 4 7 7 8 9 9 24 | 2 3 4 8 8 25 | 1 2 6 6 6 6 8 9
February 23, 2014

Physics
Sherlock Holmes examines a clue by holding his magnifying glass (with a focal length of 26.5 cm) 15.1 cm away from an object. Find the image distance. Answer in units of cm
February 21, 2014

Chemistry
Thank you!
February 10, 2014

Chemistry
A 76.00-pound flask of mercury costs $151.50. The density of mercury is 13.534 g/cm3. a) Find the price of one cubic inch of mercury by calculating the following intermediate values. What is the price of one pound of mercury? =$1.99 What is the price of one gram of mercury? =$...
February 10, 2014

Chemistry
A 76.00-pound flask of mercury costs $151.50. The density of mercury is 13.534 g/cm3. a) Find the price of one cubic inch of mercury by calculating the following intermediate values. What is the price of one pound of mercury? =$1.99 What is the price of one gram of mercury? =$...
February 10, 2014

Chemistry
A 76.00-pound flask of mercury costs $151.50. The density of mercury is 13.534 g/cm3. a) Find the price of one cubic inch of mercury by calculating the following intermediate values. What is the price of one pound of mercury? =$1.99 What is the price of one gram of mercury? =$...
February 10, 2014

Math Urgent help please
A lamppost casts a shadow of a man who is standing 15 feet away from the lamppost. The shadow is 5 feet long. The angle of elevation from the tip of the shadow to the lamp is 50. To the nearest foot, the lamppost is _____ feet tall. (Points : 2)
February 10, 2014

SICK
no matterfact I am sorry im not going to argue with teachers because that is very wrong.but I can give you all links to questions I posted through out the week with no answers??
February 1, 2014

SICK
ive been posting the same question for 2 days and you guys have been ignoring me no joke -_-
February 1, 2014

Math
Angie read 2 books in 5 days, and each book contained 340 pages. If Angie read the same number of pages each day, how many pages did she read per day? A.)75 B.)340 C.)680 D.)136
February 1, 2014

social studies(CHECK ASNWERS)
please check my answers and if there wrong maybe you could tell me the correct one.but thanks anyways. 1. How did the formation of the National Action Party change Mexican politics? A.It ended the one-party system. B.It consolidated power among a few key leaders. C.It ended ...
January 31, 2014

socialstudies(CHECK ANSWERS)
PLEASE CHECK MY ANSWERS please check my answers and if there wrong maybe you could tell me the correct one.but thanks anyways. 1. How did the formation of the National Action Party change Mexican politics? A.It ended the one-party system. B.It consolidated power among a few ...
January 31, 2014

chemistry
Need help balancing this chemical reaction equation Ca(NO3)2+2NaOH>Ca(OH)2+2NaNO3
January 30, 2014

Calculus
Find the critical numbers of the function. h(t) = t3/4 − 5t1/4
January 28, 2014

Calculus
A poster is to have an area of 160 in2 with 1 inch margins at the bottom and sides and a 7 inch margin at the top. What dimensions will give the largest printed area? (Give your answers correct to one decimal place.)
January 28, 2014

Calculus
Find the absolute maximum and absolute minimum values of f on the given interval. f(x) = (x2 - 1)3 [-1, 6]
January 28, 2014

Calculus
Find the absolute minimum and absolute maximum values of f on the interval below. f(x) = x4 - 8x2 + 6 [-3, 4]
January 28, 2014

Calculus
Find two numbers whose difference is 132 and whose product is a minimum.
January 28, 2014

Calculus
A box with a square base and open top must have a volume of 4,000 cm3. Find the dimensions of the box that minimize the amount of material used.
January 28, 2014

Calculus
A poster is to have an area of 160 in2 with 1 inch margins at the bottom and sides and a 7 inch margin at the top. What dimensions will give the largest printed area? (Give your answers correct to one decimal place.)
January 28, 2014

Please help with Physics Quickly
1. How are impulse and momentum related? (Points : 1) Impulse is the change in momentum of an object. Momentum is the change in impulse acting on an object. Impulse and momentum are always equal in magnitude. Impulse and momentum are the same thing. Question 2. 2. Which of ...
January 27, 2014

Psychology
Within each gene, elements of DNA are arranged in a particular order, forming a code that influences the synthesis of particular proteins. This code affects every aspect of the body, from its structure to the chemicals that keep it running. The above process describes:
January 27, 2014

chemistry
What is the concentration of a solution, in gsolute/100gsolvent, made using 2.29 g of KNO3 in 2.03 g of H2O?
January 24, 2014

literature
Can someone help me in scansion of the poem "the poplar field" by William Cowper? need help to find base meter, scheme, stanza forms if any, and the metrical peculiarities such as end-stopped lines, run-on lines, elision, pause, feminine ending, masculine ending and ...
January 15, 2014

Math
the length of a rectangle is seven less than four times the width. Find the length if the area is 65 square units.
January 11, 2014

physics
A mass M of 7.00E-1 kg slides inside a hoop of radius R=1.30 m with negligible friction. When M is at the top, it has a speed of 5.47 m/s. Calculate the size of the force with which the M pushes on the hoop when M is at an angle of 39.0°.
December 24, 2013

language arts
#4. C
December 18, 2013

language arts
This the passage for #2 &3: I checked into a hotel called the Olympia, which is right on the main street and the only hotel in the town. After lunch I was hanging around the lobby, and I got to taking to the guy at the desk. I asked him if this wasn't the town where that ...
December 18, 2013

Physics
A stone is thrown vertically upward at a speed of 27.70 m/s at time t=0. A second stone is thrown upward with the same speed 2.140 seconds later. At what time are the two stones at the same height? At what height do the two stones pass each other? What is the downward speed of...
December 17, 2013

Physics
A stone is thrown vertically upward at a speed of 27.70 m/s at time t=0. A second stone is thrown upward with the same speed 2.140 seconds later. At what time are the two stones at the same height? At what height do the two stones pass each other? What is the downward speed of...
December 17, 2013

physics
A stone is thrown vertically upward at a speed of 27.70 m/s at time t=0. A second stone is thrown upward with the same speed 2.140 seconds later. At what time are the two stones at the same height? At what height do the two stones pass each other? What is the downward speed of...
December 15, 2013

Math
wait what does short mean?
December 11, 2013

Algebra
A roadside vegtable stand sells pumpkins for $5 each and squashes for $3 each. One day they sold $6 more squash than pumpkins, and their sales totaled $98. Write and solve a system of equations to find how many pumpkins and squash they sold?
December 10, 2013

Chemistry
In a solution with carbon tetrachloride as the solvent, the compound VCl4 undergoes dimerization: 2VCl4 <-> V2Cl8 When 6.6834 g VCl4 is dissolved in 100.0 g of carbon tetrachloride, the freezing point is lowered by 5.97*C/ Calculate the value of the equilibrium constant ...
December 10, 2013

21
help me 9th gradge
December 4, 2013

math
45yards/minutes=______in./s
December 2, 2013

PRE-ALGEBRA
A 55-minute long distance phone costs 2.75.What is the cost per minute
December 2, 2013

Math help, anyone?
Solve the proportion. Where necessary, round to the nearest hundredth. Plz help i really need 2 get this in!! 11. 9/10 = x/10 9 *** 90 10 100 12. x/4 = 6/7 168 0.21 28 3.43 13.Write the ratio as a fraction in simplest form. 22:36 14. Write the ratio as a fraction in simplest ...
November 26, 2013

Biology
What do you think, is it likely that we will insert genes for new and better properties in humans? Is it desirable? What dangers can you see with such a development?
November 26, 2013

Plz help :(
Mrs. Sue plz help!!!
November 25, 2013

Science
Luis wanted to create a clay model of earth and the sun. To show how Earth rotates, Luis wants to use a toothpick to represent Earth's axis of rotation. Where should Luis place the toothpick? A. Horizontally through Earth in the direction Earth is traveling B. Vertically ...
November 20, 2013

US History
What times is Paine referring to? “These are the times that try men's souls. The summer soldier and the sunshine patriot will, in this crisis, shrink from the service of their country; but he that stands it now, deserves the love and thanks of man and woman."
November 16, 2013

US History
What is Patrick Henry referring to when he states : "Their clanking may be heard on the plains of Boston"?
November 14, 2013

US History
What does Patrick Henry mean when he writes "Shall we acquire the means of effectual resistance, by lying supinely on our backs..."
November 14, 2013

US History
thanks again
November 12, 2013

US History
What is Thomas Jefferson trying to say in this excerpt from the Declaration of Independence ? :The Right of the People to Control Their Government . . . We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain...
November 12, 2013

US History
thank you so much i was having problems because i dont speak the way that he speaks but thank you so much
November 12, 2013

US History
What does this excerpt from Common Sense by William Paine mean: But there is another and greater distinction for which no truly natural or religious reason can be assigned, and that is, the distinction of men into KINGS and SUBJECTS. Male and female are the distinctions of ...
November 12, 2013

Physics
n,bhyguftchg vb
November 12, 2013

math
Yes
November 12, 2013

Business
$1,604,505
November 5, 2013

math
Slope intercept form is y=mx+b m- slope b- y-intercept To finish this problem, you have to find what the y-intercept is. Just put in what you know first, and try to figure out b. 3=4(-3)+b 3= -12 =b +12 +12 15=b You can know see that 15 is b, and you can fill in the slope ...
November 4, 2013

5TH GRADE Math
To find the common factor of something, you have to post all the factors of each number. For #1 you would do: 1- 1 4- 1, 2, 4 8- 1, 2, 4, 8 32- 1, 2, 4, 8, 16 Obviously the first one is 1. A easy way to find the common factor of these questions, is simply by seeing the first ...
November 3, 2013

Organic Chemistry
3.What would be the major product if 1,4-dibromo-4-methylpentane was allowed to react with: a)One equivalent of NaI in acetone? b)One equivalent of Silver Nitrate in ethanol?
November 1, 2013

Science
how does energy provided by the sun influence global weather patterns?
October 26, 2013

Science
thank you!
October 26, 2013

Science
How is earth like a system?
October 26, 2013

english
Which one of the following sentences is correctly punctuated? A. Look up, look down, and look all around? B. Smile when you say that, Partner? C. When will the winter end? D. Look at me, then say what you have to say?
October 20, 2013

math
Do the math your selves you K12's!
October 15, 2013

Science
Calculate the amount of energy in the form of heat that is produced when a volume of 3.56 L of SO2(g) is converted to 3.56 L of SO3(g) according to this process at a constant pressure and temperature of 1.00 bar and 25.0 °C. Assume ideal gas behavior.
October 15, 2013

chemistry
Calculate the amount of energy in the form of heat that is produced when a volume of 3.56 L of SO2(g) is converted to 3.56 L of SO3(g) according to this process at a constant pressure and temperature of 1.00 bar and 25.0 °C. Assume ideal gas behavior.
October 15, 2013

calculus
Determine the value(s) of x where the function will have an instantaneous rate of change of 14. (Enter your answers as a comma-separated list. If an answer does not exist, enter DNE.) f(x) = x3 + 33 x2 + 14 x + 39
October 3, 2013

math
A NUMBER X IS INCREASED BY 27 AND THE RESULT IS MULTIPLED BY 6 GIVING 372 AS THE RESULT
October 3, 2013

math,pre algebra
Apples sell for 1.29 a pund and there is an average of 3 apples per pund.About how many apples would you expect to get for 5.00
October 3, 2013

Math
During a week-long dry spell,the water level in a pond decreased by 4 inches per day except for two days when it decreased by half of that amount. How much did the water level decrease in the pond in one week?
September 30, 2013

Spanish
Thanks btw what would gusto mean?
September 30, 2013

Spanish
I dont get what word to choose: Estudias mucho, ¿ (blank)? Do I fill it in with verdad or gusto? Why?
September 30, 2013

chemistry 1405
how to write a nuclear equation for the nuclear decay of Ra-226 to an isotope of radon-222
September 25, 2013

Physics
A bicyclist makes a trip that consists of three parts, each in the same direction (due north) along a straight road. During the first part, she rides for 21.0 minutes at an average speed of 9.48 m/s. During the second part, she rides for 43.5 minutes at an average speed of 3....
September 17, 2013

science
'The subscripts in the chemical formula for a molecular compound are not always in the lowest ratio.' Using what you know about naming binary molecular compounds, provide evidence that supports this statement.
September 14, 2013

English
i have to take out embellishments, misquotations,false benefits and unethical tactics out of these sentence can some one help me All customers qualify for the maximum discount available.
September 8, 2013

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