Friday

August 26, 2016
Total # Posts: 725

**Chemistry-help needed**

1) Does Alumnium react with steam to give metal oxide and hydrogen gas? 2) Does Aluminium react with dilute hydrochloric acid? What are the products? 3) Will Tin react with dilute hydrochloric acid to give tin(II)chloride and hydrogen gas?
*January 28, 2009*

**Science**

"Blow up a balloon and tie it up. Leave it for a few days. After a few days, the balloon becomes smaller.Why?" The answer given is that the air particles diffuse out of the balloon. Can you please explain the answer? I understand that diffusion involves particles ...
*January 28, 2009*

**science-chemistry**

For diatomic molecule, must the 2 atoms be of the same element, e.g H2?Is CO a diatomic molecule?
*January 27, 2009*

**Science**

1) Instead of using the word "random",is it acceptable to say particles in a liquid move about in "different" directions? 2) Why does ice have a higher density than water vapour? Is it because ice has a greater mass in a fixed volume? 3) The statement "...
*January 26, 2009*

**Science-Chemistry**

1)Fill in the blanks. In a liquid, particles are _____arranged. They move about in ____ directions and slide over one another. Can I say "irregularly" & "any" as the answers? I know "random directions" is better, but can we accept "any ...
*January 26, 2009*

**chemistry**

thank you.
*January 22, 2009*

**chemistry**

In an atom, there is a force that holds the protons & neutrons in the nucleus. Is this force called the nuclear force? What about the force of attraction between the nucleus and electrons? Is is called the electrostatic force of attraction?
*January 22, 2009*

**Chemistry**

If you look at the Periodic Table,you will see chlorine with a relative atomic mass of 35.5. That means the average mass of a chlorine atom found in nature is ________?
*January 22, 2009*

**Home School. PLEASE HELP ME!!**

4. is A its on page 36
*January 19, 2009*

**computers**

I was wondering if anybody could please tell me what I need to do I went to work on my power point project and when I turned on my computer a lot of my icons were missing such as my excel power point microsoft office 2007 my documents pictures my back ground ( wall paper is ...
*January 16, 2009*

**Physics**

What are the differences between a motor and a generator? I know they both use electromagnets, but how do they use them differently?
*January 10, 2009*

**Physics**

If the current in a wire is 0.1A, how long will it take for 10C of charge to pass through it?
*January 3, 2009*

**natural logs**

can't use a graphing calculator (not allowed). I'm trying to find the area between curves, if that helps.
*December 19, 2008*

**natural logs**

Solve for x: ln(x+1)+ 2 = x^2 – 8x + 12
*December 19, 2008*

**African and Hispanic Studies**

What is Jim Cummins' "Intervention Model" all about. Present the elements of this model and in your opinion, can it be successful in reversing the history of failure the Puerto Rican children have experienced in the American schools? Illustrate some of the ...
*December 17, 2008*

**PHysics**

a 15g bullet strikes and becomes embedded in a 1.1kg block of wood placed on a surface in front of the gun. if the coefficient of kinetic friction between the block and the surface is 0.25 and the impact drives the block a distance of 95m before it comes to rest, what was the ...
*December 6, 2008*

**chem-help**

I got that A was Cl2 and B was CH2 but i do not understand how to get the grams of C produced, i am confused at this point.
*December 3, 2008*

**chem-help**

no i did identify compounds A and B i just do not understand how to do part a
*December 3, 2008*

**chem-help**

Use the following information to identify element A and come pound B, then answer questions a and b. An empty glass container has a mass of 658.572 g. It has a mass of 659.452 g after it has been filled with nitrogen gas at a pressure of 790. torr and a temperature of 15°C...
*December 3, 2008*

**5th grade**

There are 7 girls in a bus. Each girl has 7 backpacks. In each backpack, there are 7 big cats. For every big cat there are 7 little cats. Question: How many legs are there in the bus?
*November 24, 2008*

**Chemistry**

Thanks!
*October 27, 2008*

**Chemistry**

Hi, This is one of my chem hw problems. Does anyone have links to websites that might help me solve this..or equations? It sounds like there are two parts to the question but I'm not sure. Volts and Joules? 1. Electrons are used to determine the structure of crystal ...
*October 27, 2008*

**math help**

Is it supposed to be 5 square root of (x ^7 and y^4)? It should be 5 then you expand everything in the sqroot to be (x x x x x x x y y y y) Then take out for every two of each letter, make it one whole one..... so you get 5 x^3 y^2 squareroot (x) I think that's what it ...
*October 26, 2008*

**algebra 2**

You should just subtract it as that .... -6 sqroot 7
*October 26, 2008*

**History**

Thank you for helping me.
*October 20, 2008*

**History**

How many times has the U.S Constitution been altered over the past 200 years?
*October 20, 2008*

**Chem/Physics**

1. The half-life for the (first-order) radioactive decay of 14C is 5730 yr (it emits a β ray with an energy of 0.16 MeV). An archaeological sample contained wood that had only 72 percent of the 14C found in living trees. What is its age? I got 500years? 2. The ...
*October 15, 2008*

**Chem/Physics**

Hi! I'm having lots of trouble figuring these two out.....if you could help that would be great- thanks!! 1. The half-life for the (first-order) radioactive decay of 14C is 5730 yr (it emits a β ray with an energy of 0.16 MeV). An archaeological sample contained wood ...
*October 15, 2008*

**Physics: Non uniform motion**

thanks! but what do i do when the time isnt given like in the first question?
*October 2, 2008*

**Physics: Non uniform motion**

I have not done much physics before: I don't get how to do questions that deal with what happened in a particular SECOND So questions like: - A stone which is dropped from rest into a mine shaft falls a distance of 24.5 m DURING THE LAST SECOND. Find depth of the shaft or...
*October 2, 2008*

**Physics**

1) A fish jumps out of the water with a speed of 6.36 m/s. If the fish is in a stream with water speed = to 1.5 m/s, how high can the fish jump if it leaves the water traveling vertically upwards relative to the earth? 2)A ball is thrown by someone on a train moving at 10 m/s ...
*September 9, 2008*

**health**

what is the definition of social and physical health?
*September 3, 2008*

**Algebra**

Solve:25x^4-20x^2+3=0 =(sqrt5/5),-(sqrt5/5),(sqrt15/5),(-sqrt15/5). Can you tell me which one is correct.This is a second post to the first one.
*July 5, 2008*

**Algebra**

Thanks
*July 5, 2008*

**Algebra**

thanks
*July 5, 2008*

**Algebra**

25x^4-20x^2+3=0 = x= i sqrt3/5,-i sqrt3/5. I used the method complete the square. is this is correct
*July 5, 2008*

**help**

thanks
*July 2, 2008*

**help**

Subtract. Simplify by collecting like radical terms if possible. 3sqrt18-3sqrt2 =6sqrt2 I did help.
*July 2, 2008*

**Algebra**

thanks
*July 1, 2008*

**Algebra**

Use the foil method to find the product. (4x^6-7)(x^8-4) this is the answer that I got:4x^14-7x^8-16x^6+28
*July 1, 2008*

**Algebra 1**

PERFORM THE INDICATED OPERATIONS AND SIMPLIFY. x-8/x-9-x+1/x+9+x-27/x^2-81=x^3-81x^2-7x-27/x^2 Can you check this equation for me.
*June 30, 2008*

**dog behavior re post**

please check my answer thanks so much Which of the following best describes when extinction occurs A When a CS is repeatedly prsented and periodically followed ba a US B When a CS is repeatedly presented without the prsention of a US C CS and US are presented together D CS is ...
*June 17, 2008*

**dog behavior**

please check my answer thanks so much for your help. True of False generalization means The tendecy to respond to stimuli resmbling the conditioned stmulus I said True
*June 17, 2008*

**dog behavior**

please check my answer thank you very much for your help The Premack princciple suggets that A. reinforcement is highly frustrating the dog B. A more desirable activity can serve as a reinforcer for aless desirable activity C reinforcement isn't dependent on the dog ...
*June 17, 2008*

**dog behavior**

Please check my answer thank you very much For optimal appetitive classical conditioning which of the following is not important. A The dog should be hungry B THe training enviorment should be relatively distraction free C. THe dog should be give the chane to "use the ...
*June 17, 2008*

**dog behavior**

Please check my answer thank you very much True or False Traning a dog to respond to the word "Good" as a conditioned reinforcer is accomplished by saying "GOOD" just before prsenting food I said True
*June 17, 2008*

**dog behavior**

please check my answer thank you for your help :) True or False Systematic desensitization can be used to reduce fear I said True
*June 10, 2008*

**dog behavior**

please check my answer thanks for your help :) Which of the following is an example of an unconditioned response? A. begging behavior at meal time B barking to get attention C Salivatig when food is taken ito the dog 's mouth D salavating when the dog hears the owner ...
*June 10, 2008*

**dog behavior**

please check my answer thanks for your help :) During extinction, an instrumenatl behavior may initially increase as the result of what ? A failure of the dog to obey the new instruction B. an extinction burst C. temorary defiance D. punishment resistance I said A
*June 10, 2008*

**dog behavior**

please check my naswer for me thanks for your help :) True or False Ivan Pavlov is credited with the systematic study of conditioned reflexive behavior I said True
*June 10, 2008*

**statistics**

. P(at least one head) is the same as 1 - P(no heads). Now, P(no heads) = 1/2 * 1/2 = 1/4 so P(at least one head) = 3/4. P(6) = 1/6. The total is 3/4 * 1/6 = 1/8. actually for part a is it possible the answer could be 1/8?
*June 4, 2008*

**statistics**

Another person had the exact same answers as you. This is for a major grade! Thank You!!
*June 4, 2008*

**statistics**

If you flipped a penny and a nickel, and rolled a die, what is the probability of: a. getting at least one head on the coins and a 6 on the die? b. getting a head on both coins and a 4 on the die ? c. getting a head on both coins and a 3 or a 5 on the die? d. getting a head on...
*June 4, 2008*

**Chemistry**

I dont understand how you get the mols product formed of (c) and why there are moles of a that remain unreacted
*May 31, 2008*

**english**

Are you serious? Come up with your own answers and others will help. This is a simple homework that you could get done in minutes.
*April 28, 2008*

**english**

Thanks Ms. Sue
*April 14, 2008*

**english**

When liquor was banned in 1920, hospitalizations for alcoholism and related diseases plummeted; in 1933, when Prohibition was repealed, alcohol-related illnesses rose sharply again. Legalization of cocaine, heroin, and marijuana would not curb abuse of those substances. a) ...
*April 14, 2008*

**Math**

Can someone tell me this is right? Look for the domain. f(x)=log(sub3)(5x+1) 5x+1<=0 (5x/5)<=(-1/5) x<=(-1/5) x>(-1/5) (-1/5,oo) -domain
*April 9, 2008*

**Algebra**

I am looking for the domain. f(x)=log(sub3)(5x+1) 5x+1<=0 (5x/5)<=(-1/5) x<=(-1/5) x>(-1/5) (-1/5,oo) -domain
*April 9, 2008*

**Algebra**

Can someone tell me how to find a perpendicular line -3x+5y=7 My choices are 7/5 3/5 -5/3 -7/5 I cannot figure this out
*March 22, 2008*

**Geography**

What government imposed barriers stop or hinder the export of automobiles? "export" as in shipping to other countries i think?!
*March 14, 2008*

**Calculus**

ah!!i was so dumb! i was trying to multiplying numerator and denominator by 1+Z,of course it didnt work out...haha... thankyou !!!!
*March 13, 2008*

**Calculus**

two complex numbers Z and W are related by the formula W=(Z+1)/(1-Z) what is W if Z=1.5i? thanks for the help!
*March 13, 2008*

**Calculus--complex numbers**

the complex number Z satisfies Z/(Z+4)= 3+2i Find Z. please help thx!
*March 13, 2008*

**Calculus**

solve (Z^2)+5=-4/Z^2 how do i solve it?? the answer is +2or-2, or, +or -i. but i really dont know how to get this answer.i tried to multiply both side by Z^2, but i think it just made it more comlicated and i didn't get the right answer at the end...can someone please ...
*March 12, 2008*

**Calculus--complex numbers**

thank you so much!!
*March 12, 2008*

**Calculus--complex numbers**

let z= a+bi be a complex number. it is given that the quotient (z-i)/(z-1) is purely imaginary. show that z lies on a circle and determine the centre and radius of this circle. OK, here's my working out...( i am using "X" as my times symbol) step1: (a+bi-i)/(a+bi...
*March 12, 2008*

**math**

finding the product for (7x+1)(x^2+1) and for the problem (2x+6)(x-10) Also finding the product thank you very much
*March 7, 2008*

**psychology**

Mira is a college student who lives alone in an apartment with her cat, Max. Whenever Mira walks into her kitchen and opens the squeaky drawer where Max's food is kept, he begins to salivate and runs into the kitchen, pawing at Mira to be fed. Even when Max has already had...
*March 3, 2008*

**geometry**

prove the following statements using a coordinate proof. the diagonals of a rectangle bisect each other.
*February 2, 2008*

**geometry**

place each given figure in a coordinate plane. what are the coordinates of each vertex? a) a right triangle b) an isosceles triangle
*February 2, 2008*

**Percent error?**

(your value/accepted value )* 100
*January 13, 2008*

**physics**

A projectile hits a target placed on a level field. It has arange of 37.0 m. The nagle of launch is 33.4 degrees above the horizontal. What was the initial speed?
*January 13, 2008*

**Chemistry**

Oh, I see now. I really appreciate your help :) Have a wonderful day!
*December 12, 2007*

**Chemistry**

But I got an answer of 42.5K, which means when I convert it to degrees Celsius I get 42.5K - 273 K = -23.05 degrees Celsius. Does this sound weird to you then?
*December 12, 2007*

**Chemistry**

Is it okay to have a negative temperature (in degrees Celsius) in this case?
*December 12, 2007*

**Chemistry**

drwls, if you are there, I got an answer of 42.5 Kelvin, so then that means it is a negative number if converted to degrees Celsius? Question: The heat capacity of a bomb calorimeter is 87.5 kJ/K (this value is for the total heat capacity including that of the water jacket ...
*December 12, 2007*

**Chemistry**

Hi, if anyone can give me help for any part of the question that would be great! I know how to draw the cell diagram, but am not sure what the half-reactions would be.... Here is the question: Give the cell diagram notation of the electrochemical cell that could be used to ...
*December 12, 2007*

**Chemistry - Thermodynamics**

The heat capacity of a bomb calorimeter is 87.5 kJ/K (this value is for the total heat capacity including that of the water jacket around the reaction chamber). If 67.2g of CH4 (g), is combusted under such reaction conditions, what will be the increase in temperature of the ...
*December 12, 2007*

**General Chem - Electrochemistry**

Give the cell diagram notation of the electrochemical cell that could be used to determine experimentally the dissociation constant (Kw) of water. The standard reduction potential for O2 + H20 + 4 e- ----> 4OH- is 0.40 V For other possible half-reactions, see your textbook...
*December 12, 2007*

**General Chem**

The concentration of potassium ions inside a nerve cell is around 20 to 30 times that outside the cell. Calculate the potential difference between inside and outside a nerve cell, if it depends only on this ionic imbalance.
*December 12, 2007*

**Chemistry - 1st Yr College Level**

The corrosion of iron can be thought of as an electrochemical cell reaction. Calculate the voltage difference between two points of corroding iron differing only in their partial pressures of oxygen: 0.20 atm of oxygen at one point and 0.0010 atm of oxygen at the other. The ...
*December 11, 2007*

**essay please check writeacher**

Is public civility gone? I agree with the claim that there has been a loss of public civility in today's society. This is due to the fact that many people cannot control their own emotional behavior, People are trying to be different and break with the past, and one way in...
*November 29, 2007*

**grammar**

In the sentence, "He is as sly as a fox", what part of speech is "as"? Is "as sly as a fox" an adjective? Is "sly" the object of a preposition? I am so confused. Thank you!
*November 27, 2007*

**english**

Thank you!
*November 13, 2007*

**english**

Is it great-grandma, great grandma, Great-grandma, Great-Grandma, or Great Grandma? Thanks!
*November 13, 2007*

**Physics**

Also, how does the flow of current differ from a superconductor compared with the flow in ordinary conductors?
*November 5, 2007*

**Physics**

How does a semiconductor differ from a conductor or an insulator?
*November 5, 2007*

**Chem**

this is not done in lab. it's supposed to be calculated. people, like you, fail.
*October 29, 2007*

**Chem**

I don't get how to do this: What is the pH of the solution created by combining 11.30 mL of the 0.10 M NaOH(aq) with 8.00 mL of the 0.10 M HCl(aq)? with 8.00 mL of the 0.10 M HC2H3O2(aq)? What are the pH values if you take into account that the 8.00 mL of 0.10 M Acid was ...
*October 29, 2007*

**Math**

1/5x-12=22 No answer please just walkthrough process
*October 18, 2007*

**Math**

7a-8=15a+8
*October 18, 2007*

**algebra**

solve the porportion 2/7 = x/42 the answer is below, but which one A.) 1/2 B.) 12 C.) 2/7 D.) 6 Can you help me pleeezz
*October 16, 2007*

**Physics**

pls ans. dis tnx i need help:((
*October 9, 2007*

**Algebra-One to one function**

Why is the square of an addiction : (a+b)^2 = a^2+b^2 +2ab? Write an example describing the operation.
*September 13, 2007*

**Dr.Bob (about finding the ml of ethanol)**

Calculate how much 95% ethyl alcohol will be required to dissolve 0.75g of sulfanilamide at 78 degrees Celsius.
*September 3, 2007*

**Physics**

A race car moves such that its position fits the relationship x=(5m/s) t + (.75m/s3 ) t3 where x is measured in meters and t in seconds. A)Plot a graph of position versus time. B)Determine the instantaneous velocity at t=4s using time intervals of .4s, .2s, and .1s. I'm ...
*September 2, 2007*

**Math**

A man walks a certain distance at a certain speed. If he walks 1/2 an hour faster than his usual speed, he will take one hour less to reach his destination. But if he walks 1 km an hour slower than his usual speed, he will take 3hours more to reach his destination. Find the ...
*July 5, 2007*

**physics**

A person holds a ladder horizontally at its center. Treating the ladder as a uniform rod of length 3.55 m and mass 10.31 Kg, find the torque the person must exert on the ladder to give it an angular acceleration of 0.406 rad/s2. Should I set the given angular acceleration ...
*June 4, 2007*

**bio (thnxs)**

Do transfer RNA have a poly A site? I know it is a anticodon area but I am not sure if this designates it as a poly A site. Thank you
*March 17, 2007*