Sunday

September 25, 2016
Number of results: 80,557

**Alegbra**

who ever will help me I do not understand this problem? Solve each exponential. Give the exact value of x 6^x = 1/36 3^x = 8 I really do not understand at all I have not taken algebra since 8th grade and went back to school at 67, Thank you if you wish to help me understand ...

*May 13, 2014 by Mary Ann *

**Chemistry**

How many kilojoules of heat are absorbed when 1.00L of water is heated from 18 degrees C to 85 degrees C? Can you please explain how to do this problem? I do not understand what to do, or understand the formula.

*May 19, 2010 by Sarah*

**General Chemistry**

I have two questions about this problem, I understand how it's supposed to be done but I don't understand how my teacher came to this answer, so I was wondering if somebody could confirm or deny his answer here's the problem. Below what temperature is: I2(g) --> I2(s)...

*April 22, 2007 by Vesone*

**College Math II**

Solve each problem. Find the quotient and remainder when x^2 – 5x + 9 is divided by x – 3. I don't understand how to divide and solve this problem. Can someone help me understand the steps on how to do it. Thanks.

*November 21, 2009 by Lori*

**GENERAL CHEMISTRY**

CALCULATE THE pH AND HYDROLYSIS IN 0.10 M AlCl3 SOLUTION.Ka = 1.2 X 10-5 FOR [Al(OH2)6]+3,OFTEN ABBREVIATED Al+3.TELL WHETHER pH IS ACID OR BASE.GIVE IONIC EQUATION. Help us a little by telling us how much you know to do and exactly what you don't understand about the problem...

*July 29, 2007 by SHAWN*

**Chemistry**

I am working on a solid chemistry problem, but I do understand what e^ means. Is it the elementary charge? or Faraday constant. Please help.

*November 16, 2013 by FHD*

**Chemistry**

I dont really understand these questions and their processes. And I am a bit iffy on redox reactions. For problem 3, can you show a step by step process how to do the problem? Problem 2, I do not fully understand how to do it at all. How would you know the resulted products? ...

*April 6, 2014 by Mika*

**Math And Science for Young Children**

The conventional problem-solving strategies usually taught have been: A. act out the problem, make a drawing or diagram, and solve the problem. B. look for a pattern, construct a table, solve the problem, and look back. C. understand the problem, devise a plan, carry out the ...

*January 9, 2016 by Tonya*

**Chemistry**

My teacher gave us the answer to a chemistry problem and i cannot figure out how she got the answer. Can you help me work out this problem so i can better understand it. A gas under an initial pressure of 0.60atm is compressed at a constant temperature from 27L to 3.0L. The ...

*March 19, 2012 by Steven*

**Chemistry**

I still don't understand how to do this problem; grams/molar mass I understand, but I need to see the steps CLEARLY. 43. How many moles are in 25.0 grams of potassium? Show your work and round your answer to the appropriate number of significant figures. Please, please help ...

*October 23, 2010 by mysterychicken*

**Math- Still Don't Understand!**

I do not understand how to work this problem out. I have a series of other questions that are similar, and it would really help me out if someone could help me understand how to work this problem. At the first tri-city meeting, there are 8 people from town A, 7 people from ...

*December 5, 2009 by Janet*

**College: Chemistry**

Hi there, I need help on my homework for chemistry and I do not understand the step on how to work this problem out. Please help me with this problem: On a Sunday morning while having your breakfast you determine that you need about 2.95X10^(5)J to heat water for your tea in ...

*February 15, 2009 by Mai*

**Chemistry**

I am sooo confused on how to solve this problem, can anyone help me understand? calculate the pH of 0.10 M HCI solution?

*October 1, 2009 by Jessica*

**Chemistry**

What volume would be occupied at 0°C and 1 atm by 3 mol CO₂(g)? I just might need someone to help me work this out, I would greatly appreciate it! I don't understand this chemistry problem.

*January 15, 2013 by Sara*

**chemistry**

Balance this chemical equation. Cr2O7 2-(aq) + Cu(s)---> Cr3+(aq) +Cu2+aq) I don't understand how to do this problem. Where do i begin? thank you.

*November 24, 2012 by MARY*

**Math**

I don't understand how to solve this problem: In solving the equation (x + 3)(x + 1) = 48, Eric stated that the solution would be x + 3 = 48 => x = 45or (x + 1) = 48 => x = 47 However, at least one of these solutions fails to work when substituted back into the original ...

*August 22, 2011 by Angelina*

**geometry**

i have 2 questions but i can't copy the figure for you to understand the problem. is there a way to scan it attach it and sent it to someone so I can understand? thanks.

*May 1, 2010 by jessica*

**chemistry**

calculate the density of NO3 gas at 0.970mm Hg and 35C Take 1 liter. calculate n in PV=nRT then, density= mass/volume= (n*molmassNO3)/1liter. I STILL DONT UNDERSTAND HOW TO DO IT COULD U PLEASE EXPLAIN What don't you understand about PV = nRT and how that fits your problem. Or...

*January 9, 2007 by TIFFANY*

**CHEMISTRY**

Hi! I know I asked this before, but I still don't understand how to solve the problem:"Since a hydrogen atom consists of one proton and one electron, it should have a mass of 1.763 x 10^-24 grams. Using unit factoring, calculate how may hydrogen atoms you'd have if you had 5.6...

*September 18, 2014 by Ellie*

**algebra**

Solve the following equation: k2 + 4k = 0 By factoring and By using the quadratic formula Can someone please help me to understand how to this problem...I do not understand the steps to get the correct answer. Thanks!!!

*February 28, 2010 by lena*

**math problems**

thanks alot for giving me those sites but i already know this stuff. They dont teach how to read an aritmetic problem so its confusing to me what to do with them, when sometimes its so obvious i just need someone to actually explain it to me in a diffent ways, that i might be ...

*July 24, 2007 by christina*

**Math**

I need to understand how to do the problem and not the answer. P.S. bobpursley, no offense but I didn't understand what your response meant. That information I already know but I need to know how to do the problem to get 213 as the answer. Anida won the class election by ...

*May 24, 2009 by Ninja*

**College Math II **

Solve the problem. If a manufacturer charges q dollars each for footballs, then he can sell 3000 – 150q footballs per week. Find the polynomial R(q) that represents the revenue for one week. Find the weekly revenue if the price is $8 for each football. I don't understand how ...

*November 21, 2009 by Lori*

**Math**

I have no idea how to understand quantitative comparison questions which involves the understanding of arithmetic mean. I need to understand the question first to do the problem, please explain. Thank you

*May 12, 2009 by DANA*

**CHEMISTRY**

Calculate the volume of 0.6M HNO3 necessary to neutralize 28.55 cm3 of 0.45M KOH. PLEASE SHOW ME STEPS SO THAT I CAN UNDERSTAND HOW TO SOLVE THIS PROBLEM. THANK YOU.

*March 15, 2009 by jj*

**chemistry**

how many "particles in solution" will form from each sucrose (C12H22O11) molecule added to water? Explain. I don't understand where I am supposed to start... What do I need to know to do this problem? thank you

*September 12, 2012 by Laura*

**Chemistry**

Find the mass of water (H2O) needed to react with 150 grams of potassium (K) 2K(s) + 2 H2O (g)-2KOH +H2(g) How do I get the number of moles in H2O? Desperate to understand this. I got K= 150g./39.0983=3.84 mols of K. Then would it be 3.84(2mols H2O/7.68) How do I get the ...

*October 27, 2014 by Teresa*

**algebra**

I forgot to ask my teacher how to do this problem because I got it wrong..so i need someone to help me do this problem. I don't understand it! 3(2+3x)=22-5x

*September 7, 2011 by anonymous. *

**Calculus**

Show that y= x + sinx-pi satisfies the initial value problem dy/dx=1 + cos x, y(pi)= 0 i don't understand how to do this problem. i don't know where to begin.

*November 18, 2008 by Dan*

**Algebra 2**

Can you please help me simplify this problem? It probably is an easy problem but I do not understand the way my teacher taught it. 1/ [1+(1/ x-2)]

*January 27, 2011 by Aura*

**chemistry**

The freezing-point depression is -0.930 Celsius degree. Determine the molality of the solution of an unknown nonelectrolyte in water. Please help!! I do not understand this problem!

*February 7, 2012 by vivian*

**Chemistry**

10g of NOBr were added to a 5L flask and the temperature was fixed to 350K. The following equilibrium is reached : NOBr(g)=NO(g)+1/2Br2(g);The pressure measured at the equilibrium was 0.63 atm.Determine Kp and Kc. I need help to solve this problem.I already done 50% but at the...

*September 19, 2016 by Gianna mele*

**chemistry **

do not understand this problem The Ksp of CaSO4 is 4.93× 10–5. Calculate the solubility (in g/L) of CaSO4(s) in 0.500 M Na2SO4(aq) at 25 °C.

*February 15, 2013 by Mohsain*

**math**

So i was going over a problem that i didnt understand which is What is the slope of the function described in the table below? x I y 0 | -3 2 | -2 4 | -1 6 | 0 the choices were f) -3 g) 1/2 h) 2 J) 3 i know that the answer is g because my family told me but i dont understand ...

*August 12, 2016 by Katherine*

**chemistry**

Find the mass of water (H2O) needed to react with 150 grams of potassium (K) 2K(s) + 2 H2O (g)-2KOH +H2(g) How do I get the number of moles in H2O? Desperate to understand this. I got K= 150g./39.0983=3.84 mols of K. Then would it be 3.84(2mols H2O/7.68) How do I get the ...

*October 27, 2014 by Teresa*

**math**

i dont understand how this is supposed to be layed out and how to do it in order... can someone write out the problem so i understand how to answer it, thanks!

*October 21, 2011 by Heaven*

**math problem**

last question because I do not understand or know how to do this problem which it says to add 1 and choose which is correct (A)161.27 (B)67.346 (C)160.27 (D)85.949

*July 14, 2008 by Ann*

**chemistry**

What is the activation energy for a reaction whose rate is tripled by a temperature increase from 28 to 53 C? I understand that I have to use the arrhenius equation, but how do I set it up for a problem like this?

*March 15, 2010 by Jeena*

**Math**

I really want to understand factoring, and I have a problem and the answer but I don't understand the steps to getting an answer. 3x^5-12^4+18x^3

*August 22, 2013 by Sarah*

**algebra 1**

The problem is 8n / 19 N = 190 I do not understand it the way the book is telling me. I understand the 8 x 190 but how do i get it to a "single number?" Thanks for the help

*June 9, 2010 by Kati*

**Algebra (Does any one understand special factors)?**

I do not understand special factors, the teacher on Friday tried to explain in to me in class but she went so fast, and every time we complain that we don't understand it she gets mad. So could someone please help me with at least one problem so I can understand it better, and...

*April 5, 2009 by Rae Rae*

**Chemistry Help Please**

i do not understand how to solve this problem, please help 10.0mL 0.5M sulfuric acid can neutralize what volume of 0.5M ammonium hydroxide?

*March 31, 2012 by Robert*

**Math**

I checked the problem but I didn't understand the answer how could you do?, because what happened with the fractions? Estimate the result of the following problem as a whole number: 4 1/43+2 15/16 -1 24/26+ 5 11/12 -3 3/61 Can you explain me, please....?

*January 20, 2010 by Sha*

**Math**

Ok so my problem is -3(3x+15)-(10+x)=35 After doing most of the problem I ended up getting -10x=105. I need to have a whole number as an answer but I can't understand what to do.

*December 9, 2014 by Janey *

**Math subject Calculus**

Hi there I am having some difficulties to solve this problem from my homework package and i don't understand how to approach this problem. Please help me by giving me advice on how to approach this problem. Let z = xsin(x/y), y does not equal zero. Show that the tangent plane ...

*October 24, 2009 by shylo*

**math - Please help me to understand**

The average selling price of homes in a certain city is $356,300. Assume the variable is normally distributed with a standard deviation of $64,600. If 396 homes are for sale, how many homes will sell for more than $325,000? (Round up to the next whole number.) I don't ...

*November 28, 2011 by Jennifer*

**math - Please help me to understand**

The average selling price of homes in a certain city is $356,300. Assume the variable is normally distributed with a standard deviation of $64,600. If 396 homes are for sale, how many homes will sell for more than $325,000? (Round up to the next whole number.) I don't ...

*November 29, 2011 by Jennifer*

**Chemistry**

Predict the standard cell potential and calculate the standard reaction Gibbs free energy for galvanic cells having the following cell reactions: 2H2+O2=2H2O in acidic solution 2H2+O2=2H2O in basic solution I understand the idea behind the problem, but I am not sure how the ...

*March 10, 2014 by Anonymous*

**chemistry**

This question I really don't get it. I tried tried tried to figure out how to start solve the problem but still couldn't figure out. So can you help me with one question PLEASE? If so, can you please explain to me how you get the answer? Also can you show me step by step of ...

*June 14, 2012 by Laura*

**Chemistry**

IF the rate of consumption of N2)4 (below) is .0221, what is the rate of production of NO2? N2O4(g)<->2NO2(g) Please help and explain. BC i have to actually understand how to do the problem. Thanks

*January 23, 2011 by Amber*

**Math**

I am in Calculus and am currently learning how to find the Area of a Surface of Revolution. I cannot understand what the surface of revolution (whether it's the x-axis, y-axis, or y=6) is. For example, I had a problem saying to use the washer method to find the volume of the ...

*December 13, 2007 by Suzie*

**LIFE ORIENTATION**

In 10-15 lines critically discuss ways in which the human or environmental problem impacts on the community regarding HIV/AIDS...The problem is that i dont understand the question

*May 15, 2011 by PETUNIA*

**Chemistry**

I am having a hard time working with moles. I understand what it is but when it is incorporated in a problem, I get confused. Can u please give me sites that have practice Moles problems?

*March 10, 2008 by Monna*

**chemistry**

A radio station's channel, such as 100.7 FM or 92.3 FM, is actually its frequency in megahertz (MHz), where 1 MHz =10^6 Hz}. Calculate the broadcast wavelength of the radio station 98.70 FM. can someone please explain this question for me, i tried several times and all 3 of my...

*October 23, 2010 by risha*

**Pre calculus**

How do I solve this exponent problem? I understand the exponent rules, but I getting 1 but 1 is not the answer! I don't want anyone to solve the problem for me, I want to learn how to solve this type of problem. Thank you! Solve the equation: -8=-3-6 (3sqrtx^2) Thanks again!

*March 27, 2013 by anon*

**Chemistry**

If one gross of golf tees weighs 118.80 grams, and a pack of golf tees weighs 412.50 g, how many golf tees are in the pack? I know that the answer is 500 golf tees, but I don't understand how this answer was achieved. Please help me understand what I'm supposed to do in this ...

*November 15, 2009 by me*

**chemistry**

i need help to understand the problem.. what is the relationship between the numbers of electrons gained and lost in a redox reaction? Do all electrochemical cells involve redox reactions?

*November 16, 2013 by S1D*

**Chemistry**

For the reaction ? Li+? N2 →? Li3N , what is the maximum amount of Li3N which could be formed from 11.79 g of Li and 17.08 g of N2? I got 19.72 g as my final answer and I just want to make sure I am correct. If I am not can you please help me understand this problem?

*August 14, 2015 by Allie*

**math,algebra**

Can someone help me with this problem I don't understand what to really do or even how to graph them I show what i have so far. Directions: Solve each of the following systems of linear inequalities graphically. Problem:

*January 2, 2007 by jasmine20*

**5th math**

what is the average number of hot dogs sold? 12,12,13,17,21,22,22,22,22,30,32,37. please! show me this how to solve this problem? my last question for today.thank you very much without your help . it;s impossible to understand this problem.

*January 27, 2011 by pat*

**Chem 1120 **

The KC for the reaction I2 --> 2I is 3.8 x 10 ^ -5 at 727 degrees C. Calculate Kc and Kp for the equilibrium of 2I -> I2 at the same conditions. I don't understand how to set up or solve this problem. I know Kc=[I]^2 / [I2] = 3.8x10^-5 for the first equation but I don't ...

*July 13, 2014 by Maddie*

**Physics**

The maximum depth of Lake Baikal, in Russia, is 1637 m, making it the world's deepest freshwater lake. If a beam of light with an angle of incidence of 60.0 degrees enters the water from the air, what is the horizontal distance between the point where the light enters the ...

*February 19, 2011 by Ashley*

**physics**

Four point charges are located at the corners of a square with sides of length a. Two of the charges are +q, and two are -q. Find the magnitude and direction of the net electric force exerted on a charge +Q, located at the center of the square, for each of the following ...

*February 26, 2016 by need help*

**chemistry**

I have been having a problem with solving a chemistry problem. The problem requires finding the density in copper at 1305K (the temperature changes when you reset the problem). I think I am using the proper formula, (N_v/N_s=Ae^-changeH_v/kT). My results are a very large ...

*November 17, 2013 by Al*

**chemistry**

I have been having a problem with solving a chemistry problem. The problem requires finding the density in copper at 1305K (the temperature changes when you reset the problem). I think I am using the proper formula, (N_v/N_s=Ae^-changeH_v/kT). My results are a very large ...

*November 17, 2013 by Al*

**Algebra 2**

Two days ago "Steve" helped me with this problem. I am grateful to him. I didn't get it and asked for him to help me again. He showed it to me again, but I needed more steps shown. Then I think he was finished for tutoring for the day before I could see it again with more ...

*January 12, 2013 by Bart*

**Chemistry**

I don't understand how to do this problem. You mix 1.00 L of 2.00 M BaCl2 with 1.00 L of 2.00 M AgNO3. What compounds remain in the solution, and what are their concentrations? BaCl2 + 2AgNO3 ---> 2AgCl + Ba(NO3)2 Is it trying to trick me with the two sets of information?

*April 29, 2010 by Ana*

**Algebra**

I am having such a hard time in this class. Hopefully someone here can help me to understand some of what they are trying to teach me. I have a problem here and have been working on it for about an hour now and I can not figure it out. I need to come up with an answer but I ...

*February 15, 2010 by Stephanie*

**Chemistry**

The speed of light is = 3x10^8 m/sec. How long will it take to reach Pluto, 278,000,000,000 km away? I don't understand how to set this problem?

*September 24, 2011 by Bob*

**Chemistry**

The speed of light is = 3x10^8 m/sec. How long will it take to reach Pluto, 278,000,000,000 km away? I don't understand how to set this problem?

*September 24, 2011 by Bob*

**4 grade math**

i need help on this problem. make 36/9 into a false number sentence? please! help me to understand this math problem thank you for your kindness.

*November 3, 2009 by samie*

**Math- HELP!**

If f(x)=3x^2 -2x -3, let g(x)=f^-1(x). Find the slope of g(x)=f^-1(x) at the point (5,2). a.) g'(5)=1/10 b.) g'(5)=1/5 c.) g'(5)=1 d.) g'(5)=2 I can't understand how to figure out this problem because I am unable to find a derivative for the function. How do I do this problem...

*July 2, 2016 by Ellie*

**chemistry**

I need help with the equilibrium constant, i understand it but I dont understand the last step when you have to change or find the exponent?

*April 6, 2011 by HS*

**CHEMISTRY**

Water has a van der Waals constants of a = 5.464 L·atm/mol2 and b = 0.03049 L/mol. What is the pressure of 5.20 moles of water vapor in a 1.10 L container at 100.0°C? I Dont understand this problem!

*May 10, 2009 by Kerrie*

**Chemistry**

A 43 sample of water absorbs 302 of heat. If the water was initially at 29.8, what is its final temperature? i been trying to solve this problem all day long, but i just don't understand how to do it. please help me. thanks..

*February 5, 2010 by mari*

**Chemistry**

What is the concentration of CrO22 4 in 0.0040 M Ba(NO3)2 saturated with BaCrO4. Including the activity coefficients in the expression? The ksp of BaCrO4 is 1.17 x10^-10 [CrO4 2-]= ? M I want to understand the problem not just the answer please.

*May 23, 2011 by Nadia*

**chemistry**

calculate the amount of heat released when 77.0g of steam at 104.5 celsius cools to ice at 0.0 celsius. I don't understand the steps to take to solve this problem. Can someone walk me through it please?

*November 12, 2014 by Loretta*

**Math**

I posted this problem the other day and someone answered it but when I checked my book I realized that I wrote the problem wrong. This morning when I posted I had put the wrong answer. The answer is suppose to be 1/8 but I don't understand how to solve the problem. Help would ...

*January 23, 2010 by Josh*

**Chemistry**

I do not understand the acid + base ->conjugate base + conjugate acid Please explain it to me with an example. I really do not understand it and I truly need your help. I do not understand how he hydrogens transfer and stuff like that. Your help is very much appreciated! ...

*March 24, 2013 by Krystien*

**Algebra 2 Problem**

The sides of a rectangle have lengths x+9 and widths x-3. Write an equation that describes the perimeter, P, of the rectangle in terms of x. I do not understand this problem, could someone please help me?

*January 12, 2012 by Isabella*

**math **

okay so I have to work out this problem for school work and I don't understand it. the problem is : if the perimeter of an isosceles triangle is 2x + 10, what is the length of one of the congruent sides ? PLEASE HELP ME !

*June 18, 2014 by kayla *

**chemistry**

To what volume must a solution of 83.1 g H2SO4 in 505.3 mL of solution be diluted to give a 0.28 M solution? I do not understand this problem. Also as a hint the professor said to use M1V1= M2V2.

*April 28, 2011 by tina*

**Chemistry**

A 32.5g cube of aluminum initially at 45.8 C is submerged into 105.3g water at 15.4 C. What is the final temp of both substances at thermal equilibrium. Assume the al and the H2O are thermally isolated from everything else) Specific heat cap Al= .903 Specific heat cap H2O= 4....

*April 24, 2011 by Phillip*

**5th Grade Math**

0.38 = (3 X 0.1) + ( X ) My sons paper instructs us to fill in the missing values. We understand that we are to fill in the two values in the second set of parenthesis, but that is all we understand. Please help...I feel so inadequate because I can't help my child with this ...

*September 7, 2010 by Sabrina*

**math**

what is the slope of the graph? what does it mean in the context of the problem? the slope for the problem is 2 i don't understand the second question then it says what is the y-intercept and what does the y-intersept represent. for the problem the y-intercept is 3, the second...

*April 1, 2013 by lily*

**math**

what is the slope of the graph? what does it mean in the context of the problem? the slope for the problem is 2 i don't understand the second question then it says what is the y-intercept and what does the y-intersept represent. for the problem the y-intercept is 3, the second...

*April 1, 2013 by lily*

**chemistry**

I really don't understand rate law. Could you explain that and help with this problem please? Determine the average rate of change of B from t=0 s to t=202 s. A-->2B Time (s) Concentration of A (M) 0 0.74 101 0.45 202 0.16

*March 23, 2012 by Katie*

**chemistry**

How do these things shift the direction of a chemical reaction?: -adding/removing reactants -adding/removing products -adding/removing energy Thanks! It depends upon the equation and whether the reaction is exothermic or endothermic. Post the entire problem and tell us what ...

*March 15, 2007 by Mira*

**anayltical chemistry**

I have tried and tried to use the henderson-hasselbalch equation for this problem, but i do not understand how to plug in the data: how much ammonium sulfate should be added to 500mL of .3M ammonia to produce a buffer with a pH of 9.?

*November 22, 2010 by joey*

**high school**

Math problem: Anida won the class election by margin of 5-3. She received 355 votes. How many votes did the other candidates get? I really need to understand how you did the problem to get the answer

*May 24, 2009 by Ninja*

**Chemistry**

Okay so I kinda understand where to put the numbers into the formula but i'm not sure how to calculate the distance so could someone kindly walk me through the problem so i can understand it. Thank you so much. Calculate the amount of energy required for the formation of one ...

*November 3, 2011 by Amanda*

**algebra**

In finding distance problems i understand the use of formula of d/rt then what i do not understand is the giving solutions in 3 decimal places. Can someone give an example step by step? The answer I do not need it is how to do it? Textbook says use calculator this is where ...

*May 28, 2010 by Mary*

**Fibonacci Numbers: Understand one part not another**

I understand how to use a calculator to write the decimal point using the golden ratio which is 1.618034 and the conjugate is -.618034. I also know that the relationship between the decimal expansions is that everything to the right of the decimal is the same except one is neg...

*October 12, 2011 by Rachel*

**college: Chemistry**

I need help on this homework problem and I do not understand how to work on it. Please help me with this problem. The photoelectric work function of a metal is the minimum energy needed to eject an electron by irradiating the metal with light. For calcium, this work function ...

*February 15, 2009 by Mai*

**Chemistry Problem**

Consider an ionic compound, MX, composed of generic metal M and generic halogen X. The enthalpy of formation of MX is ÄHf° = –457 kJ/mol. The enthalpy of sublimation of M is ÄHsub = 121 kJ/mol. The ionization energy of M is IE = 433 kJ/mol. The electron affinity of X is EA = –...

*February 2, 2013 by Anonymous*

**I don't understand this chemistry problem?**

The question reads: Place the following elements in order of decreasing atomic size: selenium, chlorine, fluorine, rubidium, calcium, and sulfur. I looked this up on a periodic table and my answer was: Rb, Se, Ca, Cl, F, S. This is still marked wrong, and I don't know why.

*December 3, 2012 by Amy*

**Math: Differential Equations**

Solve the initial value problem y' = y^2, y(0) = 1 and determine the interval where the solution exists. I understand how the final solution comes to y = 1/(1-x), but do not understand how the solution is defined from (-infinity, 1) and not (1, infinity).

*October 9, 2014 by Anonymous*

**Chemistry**

I may need this broken down step by step to understand this problem thanks. A 20.0% by mass solution of phosphoric acid (H3PO4) in water has a density of 1.114 g/ml at 20℃. What is the molarity of the solution?

*July 11, 2016 by Andrew J. DuBois*

**Math**

I do not understand how to figure out my problem below and can not find an example in my book. Can someone give me a suggestion on how I can arrive at my answer. Problem: Write a system of inequalities whose solution set is the region shown. graph

*April 18, 2008 by Jon*

**History**

I don't understand what the problem was with international relations during the Great Depression when Franklin Roosevelt was president. something about exchange-rate stabilization. That FDR refused to take part in. Mainly, I don't know what the problem was and how he tried to ...

*October 25, 2010 by Amy*