Chemistry - March 2007

2007-03-30 07:19:06 · 8 answers · asked by John M 1

If an atom has 43 electrons, 56 neutrons and 43 protons, what is its approx. atomic mass? Is it charged? What is the name of the element? What element would you have if you took away one proton and one neutron from the nucleus of this atom?

2007-03-30 06:10:11 · 5 answers · asked by Melissa H 1

2007-03-30 05:55:52 · 4 answers · asked by Melissa H 1

2007-03-30 05:39:08 · 4 answers · asked by Peter M 1

2007-03-30 05:29:07 · 5 answers · asked by Peter M 1

2007-03-30 05:12:08 · 4 answers · asked by rocky alsatian 1

we see those objects that r made of antimatter ?

2007-03-30 05:05:31 · 1 answers · asked by rocky alsatian 1

2007-03-30 05:03:53 · 5 answers · asked by Anonymous

In my college astronomy class we discussed the big bang theory. It shot out three elements that are found in all others. What are these, I know one is carbon.

2007-03-30 04:59:07 · 5 answers · asked by teana 2

2007-03-30 04:51:29 · 3 answers · asked by xpinksoldierx 1

Apart from H2O molecules, H+ ions and OH- ions, which of the following are present in an aqueous solution of a weak electrolyte?
a) cations
b) hydrated cations
c) anions
d) hydrated anions
e) undissociated molecules

2007-03-30 04:10:09 · 5 answers · asked by on_gt 1

2007-03-30 03:08:49 · 3 answers · asked by Peter M 1

How many moles of bromide ions (Br-) are there in 662 mL of a 0.349 M solution of calcium bromide (CaBr2)?

2007-03-30 03:07:46 · 4 answers · asked by Anonymous

Which of the following compounds or elements which would you expect to dissolve in water.
Note: you can select more than one answer
1. glucose (C6H12O6)
2. paraffin wax (approximate formula C30H62)
3. sodium sulfate
4. iodine (I2)

2007-03-30 02:45:44 · 11 answers · asked by Anonymous

2007-03-30 01:52:04 · 1 answers · asked by terry m 2

2007-03-30 01:07:10 · 2 answers · asked by mogojok 1

PLEASE ANSWER FAST
i have my exams on the coming monday
i found the question in a "PROBABLE QUESTIONS" book...
i am unable to answer it!!!!!!
HELP

2007-03-29 22:29:48 · 3 answers · asked by Anonymous

A.oxidizes rapidly to form a protective coating against further deterioration.
B. is a poor conductor of electricity.
C. doesn’t readily conduct heat.
D. is an alkaline earth metal.

2007-03-29 21:14:55 · 10 answers · asked by alize 1

http://www.opednews.com/maxwrite/page.php?a=32710

Seems a fair enough question.
Does anyone know?

2007-03-29 21:04:54 · 6 answers · asked by Anonymous

The best reagent used in the conversion of ethanol to chloroethane is A]PCl3 B]PCl5 C]SOCl2 D]HCl + ZnCl2 Explain

2007-03-29 19:27:05 · 4 answers · asked by Rajchem 2

What's the percent yield of iron if 950 g of Fe3O4 underwent the reaction shown in the chemical equation below and 533 g of Fe was isolated from the reaction mixture. Fe3O4 (s) + 2 C(s) ----> 2 CO2 (g) + 3 Fe

2007-03-29 19:24:52 · 1 answers · asked by hockeyislife21 1

Hydrochloric acid can be prepared using the reaction described by the chemical equation: 2 NaCl(s) + H2SO4(l) ----> 2 HCl(g) + Na2 SO4(s). How many grams of HCl can be prepared from 393 g of H2SO4 and 4.00 moles of NaCl?

2007-03-29 19:19:22 · 2 answers · asked by crazymonkey 1

Why was it more difficult to design an experiment that would prove the existence of neutrons than it was to design an experiment that would prove the existence of either protons or electrons?

2007-03-29 18:15:41 · 4 answers · asked by crazymonkey 1

What happens if you add H2 to an alkene? Would the bonds break and would it result in an alkane? An example would be helpful. Also, is it possible to add H2 to benzene?

2007-03-29 17:57:58 · 3 answers · asked by Sgt. Pepper 2

why is the simplest formula used to determine the molar mass for ionic compounds?

2007-03-29 17:52:48 · 2 answers · asked by Anonymous

what is the ratio of N and H atoms in NH3?

what is the ratio of calcium and choloride ions in CaCl2?

2007-03-29 17:51:51 · 2 answers · asked by Anonymous

1) what is the reason of an element's having a colour?
2) the alkali and alkaline metals have colours due to electron transition. do they always go on doing this as they are always colourfull?
3) if colours are releted to absorbing of colour spectrum, what is the reason of transparency?

2007-03-29 17:43:04 · 2 answers · asked by nisha 2

Using a table of standard reduction potentials calculate the standard cell potential (electromotive force) in volts

for the following cell.


2I − + Br2 = I2 + 2Br

2007-03-29 17:27:17 · 1 answers · asked by Anonymous

Calculate the theoretical yield of water in grams that can be made rom the reaction of 250 grams of potassium hydroxide and 350 grams of sulfuric acid. Identify the limiting reagant. Calculate the number of grams of excess reagent remaining after the reaction is completed. If the actual yield of water is 60 grams, calculate the percent yield.

2007-03-29 17:24:52 · 1 answers · asked by SICK MY DUCK! 1

what is the simplest formula for cesium carbonate?

please help me i really don't get this.

2007-03-29 17:20:42 · 3 answers · asked by Anonymous