Science & Mathematics - 22 July 2007

In demonstrating the Law of Multiple Proportions, the ratio of the masses of oxygen that combine with a given mass of nitrogen in the compounds NO2 and N2O5 is

A) 3:1
B) 2:5
C) 2:3
D) 4:5
E) 2:1

2007-07-22 20:43:29 · 1 answers · asked by ~daweed~ 3 in Chemistry

2007-07-22 20:33:47 · 11 answers · asked by michelle h 1 in Mathematics

2007-07-22 20:33:44 · 8 answers · asked by Anonymous in Mathematics

1.The sum of four consecutive two-digit odd numbers, when divided by 10, becomes a perfect square.Which of the following can possibly be one of these four numbers ?
a.21 b.25 c.67 d.73


2.The number of solutions of the equation 2x+y=40 where both x and y are positive integers and x=or < y is :
a.7 b.13 c.18 d.20


Please help me, with the derivation too, I am not able to solve it, I tried so much and need help.
Thank you vey much.

2007-07-22 20:27:41 · 5 answers · asked by heartywalk 2 in Mathematics

.... letters or digits such as; 42cc,66qq,bb44, cc77?
Using numbers 0 through 9 and letters a through z

2007-07-22 20:25:42 · 3 answers · asked by donna2mph_K 2 in Mathematics

can anyone answers me if there is any other space is prevailing in my space?
its true that for any particle there is an anti-particle?pls explain to me.

2007-07-22 20:22:25 · 9 answers · asked by hot d 1 in Astronomy & Space

Certain chemical compounds attaching to receptors?

Essentially, is it more the strength of the odor/aroma or the specific type of odor?

2007-07-22 20:21:38 · 5 answers · asked by __ 3 in Biology

2007-07-22 20:14:54 · 5 answers · asked by jennifer f 1 in Mathematics

2007-07-22 20:12:49 · 2 answers · asked by jennifer f 1 in Mathematics

Ve^(-.001/x) = 0.5V ======> e^(.001/x) =2. I got this out of the solutions manual to my circuits class.

2007-07-22 20:12:15 · 2 answers · asked by tegra977 1 in Mathematics

can you explain the steps or how you did it... thank you very much...

2007-07-22 20:11:43 · 4 answers · asked by Anonymous in Mathematics

2007-07-22 20:10:24 · 3 answers · asked by Anonymous in Mathematics

Focus lens system which has no mechanical moving parts

its was recently developed by philps

dear friends do u have any information regrading this topic pl z reply

2007-07-22 19:54:38 · 1 answers · asked by nithin n 1 in Physics

I have 150ml of solution from a student's experiment in producing H2SO4. The student used a variation of Glauber's method for producing a small amount of H2SO4. (burning sulfur & NaNO3 mix to oxidize sulfur into SO2. combining SO2 with air to form SO3, then bubbling the mixture into water. This is the 17th century method. No sweet vanadium catalyst required.

Question 1: He didn't have any NaNO3, so he substituted KNO3.
Am I right that this should still work? i.e. both oxidizers will oxidize sulfur to SO2 when burned?

Now the big question. How can I determine (chemically, electrically, numerologically -anything but orally or sexually :) ) whether this 150ml solution is dilute H2SO4, H2SO3, or a mix of both?

I know both chemicals have distinguishing physical properties (H2SO3 = on-your-*** sulfurous odor), but this is so diluted, none are apparent. All I have to go on is, it's 150ml of clear liquid with no odor and pH <1.

Thanks in advance.. Again.

2007-07-22 19:52:04 · 2 answers · asked by Kelani 3 in Chemistry

How many ways are there to select five unordered elements from a set with three elements when repetition is allowed?

2007-07-22 19:39:49 · 4 answers · asked by Anonymous in Other - Science

can anyone help me find a diagram of all the muscles?

2007-07-22 19:39:09 · 1 answers · asked by Cory 2 in Biology

Mathematics is a subject which is based on reality, logic and true results. so it is prctically applied in our diifferent aspects of life. Kindly i need practical examples.

2007-07-22 19:35:58 · 14 answers · asked by arfee_shah 1 in Other - Science

What is the difference between an independent and dependent variable for statistics? How can you tell which is which? Please give me some examples.

2007-07-22 19:34:26 · 3 answers · asked by chibagrll 1 in Mathematics

2007-07-22 19:28:28 · 4 answers · asked by Mason 1 in Geography

Does heat create infrared radiation? Is heat itself IR radiation? Is it radiation like I am thinking of in the sense of nuclear radiation except not harmful? If someone could clear this up for me...what exactly is the link here?

2007-07-22 19:24:50 · 7 answers · asked by Fieyr 4 in Other - Science

2007-07-22 19:18:45 · 3 answers · asked by Anonymous in Physics

how come every time i watch a haunting story or ghost story on tv about people seeing ghost how come the people are white people all the time every time i watch a show about ghost its always white people seeing the ghost why is this?

2007-07-22 19:17:38 · 16 answers · asked by luis r 1 in Astronomy & Space

2007-07-22 19:14:56 · 11 answers · asked by luis r 1 in Astronomy & Space

How many miles is it from Sayre PA to Melbourne Australia

2007-07-22 19:14:48 · 2 answers · asked by deborah_jean_1977 1 in Geography

2007-07-22 19:09:21 · 8 answers · asked by Anonymous in Weather

(This is a basic but very fundamental question about terminology, so no stupid or disrespectful answers please.)

To how many decimal places accuracy is an approximation 'a' to a quantity 'x'?

Specifically tell me your answer to this example:
a = 3.16
x = pi = 3.14159...

Note that to 1 decimal place, a≈3.2, whereas x≈3.1
So: which of the following would be correct:
"a is x correct to 0 decimal places"
or:
"a is x correct to 1 decimal place"

What is confusing is that the error ε = a-x = +0.0184
which is < 5x10^-2, thus implying an accuracy of 2 dps.
Explain all that if you can.

Explain the reasoning behind your response clearly (and get your terms correct).

2007-07-22 19:08:38 · 4 answers · asked by smci 7 in Mathematics

Can you get neodymium magnets in sheet form and if so are sheet magnets weaker or stronger than other ones(disc, cube etc)?

2007-07-22 19:02:43 · 2 answers · asked by ntm495 4 in Physics

2007-07-22 19:00:45 · 20 answers · asked by Anonymous in Mathematics

2007-07-22 18:56:14 · 9 answers · asked by Ashley H 1 in Physics

Why Doctors do not donate blood? are there any disadvantages?

2007-07-22 18:55:32 · 6 answers · asked by as0 1 in Medicine